GCSE Maths: Multiplying and dividing terms, and the laws of indices (Higher)
Part of the GCSE Maths algebra basics chapter (Higher). Chapter overview · Foundation version of this lesson · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
Multiplying and dividing terms, and the laws of indices
You already know how to multiply numbers. Multiplying algebraic terms follows the same idea: multiply the numbers, then deal with the letters.
What is x × x? Picture a square with sides of length x. Its area is x × x, which we write as x2 (“x squared”). The little 2 is called the index or power. It says how many copies of the letter are multiplied together.
Multiplying terms
3a × 4b means 3 × a × 4 × b. Multiplication can be done in any order, so we can swap the numbers round: 3 × 4 × a × b = 12ab. When the same letter appears in both terms, count the copies. 5x × 2x = 10 × x × x = 10x2.
The laws of indices
Writing the letters out in full shows why these rules work. For example x3 × x2 = (x × x × x) × (x × x), which is five xs multiplied together, so it is x5.
| Law | Example | In words |
|---|---|---|
| am × an = am+n | x3 × x4 = x7 | multiplying: add the powers |
| am ÷ an = am−n | x5 ÷ x2 = x3 | dividing: subtract the powers |
| (am)n = amn | (x2)3 = x6 | a power of a power: multiply the powers |
| a1 = a | y = y1 | a letter on its own has power 1 |
| a0 = 1 | x4 ÷ x4 = x0 = 1 | anything (except 0) to the power 0 is 1 |
The number parts of the terms are just multiplied or divided as usual. Only the letter parts use the index laws. And when there is a power outside a bracket, it applies to everything in the bracket: (2x3)2 = 22 × (x3)2 = 4x6.
You have met these laws with numbers in Chapter 2 (for example 23 × 24 = 27). Here the base is a letter, but nothing else changes.
Dividing terms
To divide terms, divide the numbers and then subtract the powers of each letter. It is the same as cancelling. 12x5 ÷ 3x2 = 12x53x2 = 4x3. You can write a division of terms as a fraction and cancel the numbers and the letters.
Negative and fractional indices
The same laws still work when the indices are negative or fractions. A negative index means “one over”: x−2 = 1x2. A fractional index means a root: x1/2 = √x, and x1/3 is the cube root of x. These are covered with numbers in Chapter 6; here we use the laws with letters. Example: x−2 × x5 = x−2+5 = x3.
Key ideas
- Multiply terms: multiply the numbers, and add the powers of each letter. 3x2 × 4x3 = 12x5.
- Divide terms: divide the numbers, and subtract the powers. 12x5 ÷ 3x2 = 4x3.
- Power of a power: multiply the powers. (x2)3 = x6. A power outside a bracket applies to the number and every letter inside.
- a1 = a and a0 = 1.
- The laws only work when the letters (the bases) are the same.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.2a2b × 3ab3
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 2 × 3 = 6
a: add the powers 2 + 1 = 3
b: add the powers 1 + 3 = 4
So the top is 6a3b4 - Write the answer. Put the number first, then the letters.6a3b4
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 3888 and the answer gives 3888. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.5x × 2x
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 5 × 2 = 10
x: add the powers 1 + 1 = 2
So the top is 10x2 - Write the answer. Put the number first, then the letters.10x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 40 and the answer gives 40. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.15a3b25ab
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 15 ÷ 5 = 3
a: subtract the powers 3 − 1 = 2
b: subtract the powers 2 − 1 = 1 - Write the answer. Put the number first, then the letters.3a2b
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 36 and the answer gives 36. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(3ab2)3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(3ab2)3 → number: 33 = 27; a: 1 × 3 = 3; b: 2 × 3 = 6 → 27a3b6
- Write the answer. Put the number first, then the letters.27a3b6
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 157464 and the answer gives 157464. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(4x3y)2 × 3xy6x2y
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(4x3y)2 → number: 42 = 16; y: 1 × 2 = 2; x: 3 × 2 = 6 → 16x6y2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 16 × 3 = 48
x: add the powers 6 + 1 = 7
y: add the powers 2 + 1 = 3
So the top is 48x7y3 - Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 48 ÷ 6 = 8
x: subtract the powers 7 − 2 = 5
y: subtract the powers 3 − 1 = 2 - Write the answer. Put the number first, then the letters.8x5y2
Check. Test with numbers: put x = 2, y = 3 into the question and into the answer. The question gives 2304 and the answer gives 2304. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.x−2 × 3x5
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 3 = 3
x: add the powers −2 + 5 = 3
So the top is 3x3 - Write the answer. Put the number first, then the letters.3x3
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 24 and the answer gives 24. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(27x6)1/3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(27x6)1/3 → number: 271/3 = 3; x: 6 × 1/3 = 2 → 3x2
- Write the answer. Put the number first, then the letters.3x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 12 and the answer gives 12. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Watch out
Only the powers are added when you multiply. 3x × 2x = 6x2: the numbers are multiplied (3 × 2 = 6), they are not added, and the power of x goes from 1 + 1 = 2. Also x3 × x4 is x7, not x12. And x2 + x3 cannot be simplified at all: the laws are for multiplying and dividing, not for adding.Exercise 7C Multiplying, dividing and indices
Non-calculatorKey words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.4x × 3
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 4 × 3 = 12
x: add the powers 1 = 1
So the top is 12x - Write the answer. Put the number first, then the letters.12x
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 24 and the answer gives 24. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.2a × 5b
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 2 × 5 = 10
a: add the powers 1 = 1
b: add the powers 1 = 1
So the top is 10ab - Write the answer. Put the number first, then the letters.10ab
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 60 and the answer gives 60. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.x × x
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
x: add the powers 1 + 1 = 2
So the top is x2 - Write the answer. Put the number first, then the letters.x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 4 and the answer gives 4. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.3y × 2y
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 3 × 2 = 6
y: add the powers 1 + 1 = 2
So the top is 6y2 - Write the answer. Put the number first, then the letters.6y2
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 24 and the answer gives 24. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.5m × m2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 5 × 1 = 5
m: add the powers 1 + 2 = 3
So the top is 5m3 - Write the answer. Put the number first, then the letters.5m3
Check. Test with numbers: put m = 2 into the question and into the answer. The question gives 40 and the answer gives 40. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.ab × ab
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
a: add the powers 1 + 1 = 2
b: add the powers 1 + 1 = 2
So the top is a2b2 - Write the answer. Put the number first, then the letters.a2b2
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 36 and the answer gives 36. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.x3 × x4
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
x: add the powers 3 + 4 = 7
So the top is x7 - Write the answer. Put the number first, then the letters.x7
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 128 and the answer gives 128. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.a5 ÷ a2
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 1 ÷ 1 = 1
a: subtract the powers 5 − 2 = 3 - Write the answer. Put the number first, then the letters.a3
Check. Test with numbers: put a = 2 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(y2)3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(y2)3 → y: 2 × 3 = 6 → y6
- Write the answer. Put the number first, then the letters.y6
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 64 and the answer gives 64. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.p × p × p
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 × 1 = 1
p: add the powers 1 + 1 + 1 = 3
So the top is p3 - Write the answer. Put the number first, then the letters.p3
Check. Test with numbers: put p = 2 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.m6 ÷ m
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 1 ÷ 1 = 1
m: subtract the powers 6 − 1 = 5 - Write the answer. Put the number first, then the letters.m5
Check. Test with numbers: put m = 2 into the question and into the answer. The question gives 32 and the answer gives 32. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.k8 × k
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
k: add the powers 8 + 1 = 9
So the top is k9 - Write the answer. Put the number first, then the letters.k9
Check. Test with numbers: put k = 2 into the question and into the answer. The question gives 512 and the answer gives 512. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.3x2 × 2x4
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 3 × 2 = 6
x: add the powers 2 + 4 = 6
So the top is 6x6 - Write the answer. Put the number first, then the letters.6x6
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 384 and the answer gives 384. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.4a3 × 5a
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 4 × 5 = 20
a: add the powers 3 + 1 = 4
So the top is 20a4 - Write the answer. Put the number first, then the letters.20a4
Check. Test with numbers: put a = 2 into the question and into the answer. The question gives 320 and the answer gives 320. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.6b × b2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 6 × 1 = 6
b: add the powers 1 + 2 = 3
So the top is 6b3 - Write the answer. Put the number first, then the letters.6b3
Check. Test with numbers: put b = 2 into the question and into the answer. The question gives 48 and the answer gives 48. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.2y3 × 7y2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 2 × 7 = 14
y: add the powers 3 + 2 = 5
So the top is 14y5 - Write the answer. Put the number first, then the letters.14y5
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 448 and the answer gives 448. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.12x ÷ 3
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 12 ÷ 3 = 4
x: subtract the powers 1 − 0 = 1 - Write the answer. Put the number first, then the letters.4x
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.20a2 ÷ 4a
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 20 ÷ 4 = 5
a: subtract the powers 2 − 1 = 1 - Write the answer. Put the number first, then the letters.5a
Check. Test with numbers: put a = 2 into the question and into the answer. The question gives 10 and the answer gives 10. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.15y3 ÷ 5y
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 15 ÷ 5 = 3
y: subtract the powers 3 − 1 = 2 - Write the answer. Put the number first, then the letters.3y2
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 12 and the answer gives 12. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.18p4 ÷ 6p2
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 18 ÷ 6 = 3
p: subtract the powers 4 − 2 = 2 - Write the answer. Put the number first, then the letters.3p2
Check. Test with numbers: put p = 2 into the question and into the answer. The question gives 12 and the answer gives 12. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.8m ÷ 2m
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 8 ÷ 2 = 4
m: subtract the powers 1 − 1 = 0. A power of 0 means the letter has cancelled completely, because a0 = 1. - Write the answer. Put the number first, then the letters.4
Check. Test with numbers: put m = 2 into the question and into the answer. The question gives 4 and the answer gives 4. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.9t2 ÷ 3t2
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 9 ÷ 3 = 3
t: subtract the powers 2 − 2 = 0. A power of 0 means the letter has cancelled completely, because a0 = 1. - Write the answer. Put the number first, then the letters.3
Check. Test with numbers: put t = 2 into the question and into the answer. The question gives 3 and the answer gives 3. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.3ab × 2a
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 3 × 2 = 6
a: add the powers 1 + 1 = 2
b: add the powers 1 = 1
So the top is 6a2b - Write the answer. Put the number first, then the letters.6a2b
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 72 and the answer gives 72. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.4xy × 5x
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 4 × 5 = 20
x: add the powers 1 + 1 = 2
y: add the powers 1 = 1
So the top is 20x2y - Write the answer. Put the number first, then the letters.20x2y
Check. Test with numbers: put x = 2, y = 3 into the question and into the answer. The question gives 240 and the answer gives 240. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.2pq × 3pq
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 2 × 3 = 6
p: add the powers 1 + 1 = 2
q: add the powers 1 + 1 = 2
So the top is 6p2q2 - Write the answer. Put the number first, then the letters.6p2q2
Check. Test with numbers: put p = 2, q = 3 into the question and into the answer. The question gives 216 and the answer gives 216. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.a2b × ab2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
a: add the powers 2 + 1 = 3
b: add the powers 1 + 2 = 3
So the top is a3b3 - Write the answer. Put the number first, then the letters.a3b3
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 216 and the answer gives 216. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.5x2 × 3x
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 5 × 3 = 15
x: add the powers 2 + 1 = 3
So the top is 15x3 - Write the answer. Put the number first, then the letters.15x3
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 120 and the answer gives 120. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(4a)2
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(4a)2 → number: 42 = 16; a: 1 × 2 = 2 → 16a2
- Write the answer. Put the number first, then the letters.16a2
Check. Test with numbers: put a = 2 into the question and into the answer. The question gives 64 and the answer gives 64. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.2x × 3x × x2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 2 × 3 × 1 = 6
x: add the powers 1 + 1 + 2 = 4
So the top is 6x4 - Write the answer. Put the number first, then the letters.6x4
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 96 and the answer gives 96. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Method. Substitute x = 2 into the question and into Ali's answer. If they differ, Ali is wrong.
- Work out the question with x = 2. 2x = 4 and 3x = 6.4 × 6 = 24
- Work out Ali's answer with x = 2. 6x = 6 × 2 = 12
- Compare. 24 is not 12, so Ali is wrong.
- Find the correct answer. Multiply the numbers: 2 × 3 = 6. Then x × x = x2.2x × 3x = 6x2
Check. 6x2 with x = 2 is 6 × 4 = 24, which matches the question. ✓
Watch out. x × x is x2, not x.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.3x2 × 2x3
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 3 × 2 = 6
x: add the powers 2 + 3 = 5
So the top is 6x5 - Write the answer. Put the number first, then the letters.6x5
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 192 and the answer gives 192. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(x2)3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(x2)3 → x: 2 × 3 = 6 → x6
- Write the answer. Put the number first, then the letters.x6
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 64 and the answer gives 64. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(2a)3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(2a)3 → number: 23 = 8; a: 1 × 3 = 3 → 8a3
- Write the answer. Put the number first, then the letters.8a3
Check. Test with numbers: put a = 2 into the question and into the answer. The question gives 64 and the answer gives 64. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(3b2)2
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(3b2)2 → number: 32 = 9; b: 2 × 2 = 4 → 9b4
- Write the answer. Put the number first, then the letters.9b4
Check. Test with numbers: put b = 2 into the question and into the answer. The question gives 144 and the answer gives 144. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(5x)2
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(5x)2 → number: 52 = 25; x: 1 × 2 = 2 → 25x2
- Write the answer. Put the number first, then the letters.25x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 100 and the answer gives 100. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(ab)4
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(ab)4 → a: 1 × 4 = 4; b: 1 × 4 = 4 → a4b4
- Write the answer. Put the number first, then the letters.a4b4
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 1296 and the answer gives 1296. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(2y3)4
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(2y3)4 → number: 24 = 16; y: 3 × 4 = 12 → 16y12
- Write the answer. Put the number first, then the letters.16y12
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 65536 and the answer gives 65536. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.6x23x
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 6 ÷ 3 = 2
x: subtract the powers 2 − 1 = 1 - Write the answer. Put the number first, then the letters.2x
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 4 and the answer gives 4. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.10a3b5ab
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 10 ÷ 5 = 2
a: subtract the powers 3 − 1 = 2
b: subtract the powers 1 − 1 = 0. A power of 0 means the letter has cancelled completely, because a0 = 1. - Write the answer. Put the number first, then the letters.2a2
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.12xy24y
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 12 ÷ 4 = 3
x: subtract the powers 1 − 0 = 1
y: subtract the powers 2 − 1 = 1 - Write the answer. Put the number first, then the letters.3xy
Check. Test with numbers: put x = 2, y = 3 into the question and into the answer. The question gives 18 and the answer gives 18. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.15p3q23pq
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 15 ÷ 3 = 5
p: subtract the powers 3 − 1 = 2
q: subtract the powers 2 − 1 = 1 - Write the answer. Put the number first, then the letters.5p2q
Check. Test with numbers: put p = 2, q = 3 into the question and into the answer. The question gives 60 and the answer gives 60. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Method. When multiplying, the powers add.
- Write an equation for the powers. ? + 4 = 9.? + 4 = 9
- Solve. Subtract 4 from both sides.? = 9 − 4 = 5
Check. x5 × x4 = x5+4 = x9. ✓
Method. When dividing, the powers subtract.
- Write an equation for the powers. 7 − ? = 2.7 − ? = 2
- Solve. The missing number is what you take away from 7 to leave 2.? = 7 − 2 = 5
Check. x7 ÷ x5 = x2. ✓
Method. For a power of a power the powers multiply.
- Write an equation for the powers. ? × 3 = 12.? × 3 = 12
- Solve. Divide both sides by 3.? = 12 ÷ 3 = 4
Check. (x4)3 = x4×3 = x12. ✓
Method. Only the x powers matter here, since 3 × 2 = 6 already matches. Add the powers.
- Write an equation for the powers. ? + 2 = 5.? + 2 = 5
- Solve. ? = 5 − 2 = 3
Check. 3x3 × 2x2 = 6x5. ✓
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(2x2)34x4
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(2x2)3 → number: 23 = 8; x: 2 × 3 = 6 → 8x6
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 8 ÷ 4 = 2
x: subtract the powers 6 − 4 = 2 - Write the answer. Put the number first, then the letters.2x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Method. Any number (except 0) raised to the power 0 is 1. Here is why.
- Divide a power by itself. 53 ÷ 53 = 125 ÷ 125 = 1.53 ÷ 53 = 1
- Use the subtraction law for indices. The same division gives 53−3.53 ÷ 53 = 50
- Put them together. Both are the same calculation, so they are equal.50 = 1
Check. The same works for any other power: 52 ÷ 52 = 25 ÷ 25 = 1. ✓
Method. Any letter (not zero) to the power 0 is 1.
- Divide a power by itself. y4 ÷ y4 = 1 because anything divided by itself is 1.y4 ÷ y4 = 1
- Use the subtraction law. y4−4 = y0, so y0 = 1
Check. Try y = 3: 34 ÷ 34 = 81 ÷ 81 = 1. ✓
Method. The power 0 only applies to the letter next to it, not the 6.
- Replace x0 by 1. The index 0 belongs to x only.6x0 = 6 × 1
- Multiply. 6 × 1 = 6
Check. If x = 5, x0 = 1, so 6 × 1 = 6. ✓
Watch out. 6x0 is 6, but (6x)0 is 1.
Method. Everything inside the bracket is raised to the power 0.
- Raise the whole bracket to the power 0. Any non-zero quantity to the power 0 is 1.(3a)0 = 1
- Say why. It is (3a)2 ÷ (3a)2 = 1.1
Check. If a = 2: (3 × 2)0 = 60 = 1. ✓
Method. Width = area ÷ length, so divide the terms.
- Write the division. Area = length × width, so width = area ÷ length.12x3 ÷ 4x
- Divide. Divide the numbers, subtract the powers.12 ÷ 4 = 3 and x3 ÷ x = x3−1 = x2
- Write the answer. 3x2 cm
Check. Multiply back: 4x × 3x2 = 12x3. ✓
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.x−2 × x5
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
x: add the powers −2 + 5 = 3
So the top is x3 - Write the answer. Put the number first, then the letters.x3
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.3a−1 × 4a3
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 3 × 4 = 12
a: add the powers −1 + 3 = 2
So the top is 12a2 - Write the answer. Put the number first, then the letters.12a2
Check. Test with numbers: put a = 2 into the question and into the answer. The question gives 48 and the answer gives 48. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.y4 ÷ y7
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 1 ÷ 1 = 1
y: subtract the powers 4 − 7 = −3 - Write the answer. Put the number first, then the letters.y−3
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 1/8 and the answer gives 1/8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(x−2)3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(x−2)3 → x: −2 × 3 = −6 → x−6
- Write the answer. Put the number first, then the letters.x−6
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 1/64 and the answer gives 1/64. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.12p2 ÷ 4p5
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 12 ÷ 4 = 3
p: subtract the powers 2 − 5 = −3 - Write the answer. Put the number first, then the letters.3p−3
Check. Test with numbers: put p = 2 into the question and into the answer. The question gives 3/8 and the answer gives 3/8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(2x−1)3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(2x−1)3 → number: 23 = 8; x: −1 × 3 = −3 → 8x−3
- Write the answer. Put the number first, then the letters.8x−3
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 1 and the answer gives 1. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.x1/2 × x1/2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 1 × 1 = 1
x: add the powers 1/2 + 1/2 = 1
So the top is x - Write the answer. Put the number first, then the letters.x
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 2 and the answer gives 2. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(x1/2)4
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(x1/2)4 → x: 1/2 × 4 = 2 → x2
- Write the answer. Put the number first, then the letters.x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 4 and the answer gives 4. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(8x6)1/3
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(8x6)1/3 → number: 81/3 = 2; x: 6 × 1/3 = 2 → 2x2
- Write the answer. Put the number first, then the letters.2x2
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 8 and the answer gives 8. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.x3/2 ÷ x1/2
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 1 ÷ 1 = 1
x: subtract the powers 3/2 − 1/2 = 1 - Write the answer. Put the number first, then the letters.x
Check. Test with numbers: put x = 2 into the question and into the answer. The question gives 2 and the answer gives 2. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(16y4)1/2
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(16y4)1/2 → number: 161/2 = 4; y: 4 × 1/2 = 2 → 4y2
- Write the answer. Put the number first, then the letters.4y2
Check. Test with numbers: put y = 2 into the question and into the answer. The question gives 16 and the answer gives 16. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(3x2y)39xy2
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(3x2y)3 → number: 33 = 27; y: 1 × 3 = 3; x: 2 × 3 = 6 → 27x6y3
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 27 ÷ 9 = 3
x: subtract the powers 6 − 1 = 5
y: subtract the powers 3 − 2 = 1 - Write the answer. Put the number first, then the letters.3x5y
Check. Test with numbers: put x = 2, y = 3 into the question and into the answer. The question gives 288 and the answer gives 288. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(2a3b)2 × 3ab6a2b
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(2a3b)2 → number: 22 = 4; b: 1 × 2 = 2; a: 3 × 2 = 6 → 4a6b2
- Multiply the terms: first the numbers, then each letter. Multiply the numbers (coefficients) together. For each letter, add the powers, because x2 × x3 = (x × x) × (x × x × x) = x5 (the law am × an = am+n). A letter written on its own has power 1.Numbers: 4 × 3 = 12
a: add the powers 6 + 1 = 7
b: add the powers 2 + 1 = 3
So the top is 12a7b3 - Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 12 ÷ 6 = 2
a: subtract the powers 7 − 2 = 5
b: subtract the powers 3 − 1 = 2 - Write the answer. Put the number first, then the letters.2a5b2
Check. Test with numbers: put a = 2, b = 3 into the question and into the answer. The question gives 576 and the answer gives 576. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(5x2y3)210xy
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(5x2y3)2 → number: 52 = 25; x: 2 × 2 = 4; y: 3 × 2 = 6 → 25x4y6
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 25 ÷ 10 = 2510 = 52 (simplified)
x: subtract the powers 4 − 1 = 3
y: subtract the powers 6 − 1 = 5 - Write the answer. Put the number first, then the letters.5x3y52
Check. Test with numbers: put x = 2, y = 3 into the question and into the answer. The question gives 4860 and the answer gives 4860. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Key words. The power or index (plural indices) tells you how many copies of the letter are multiplied together: x3 = x × x × x. The coefficient is the number in front of the letters.
Method. To multiply terms, multiply the numbers and add the powers of each letter. To divide, divide the numbers and subtract the powers. A power outside a bracket multiplies every power inside.
- Write the question. We are going to simplify one product or quotient of terms.(4pq2)38p2q5
- Deal with any power outside a bracket first. A power outside a bracket applies to everything inside it: the number and every letter. For example (2x3)2 means 2x3 × 2x3. The number is raised to the power, and each letter's own power is multiplied by it (the law (am)n = amn).(4pq2)3 → number: 43 = 64; p: 1 × 3 = 3; q: 2 × 3 = 6 → 64p3q6
- Now divide: divide the numbers, and for each letter subtract the powers. Dividing by a term is the same as cancelling. x5 ÷ x2 = (x × x × x × x × x) ÷ (x × x) = x3 (the law am ÷ an = am−n). Divide the numbers as you would divide any numbers.Numbers: 64 ÷ 8 = 8
p: subtract the powers 3 − 2 = 1
q: subtract the powers 6 − 5 = 1 - Write the answer. Put the number first, then the letters.8pq
Check. Test with numbers: put p = 2, q = 3 into the question and into the answer. The question gives 48 and the answer gives 48. They are the same. ✓
Watch out. Add the powers when you multiply (x2 × x3 = x5, not x6). Multiply the powers when there is a power of a power. And only the powers change: 3x × 2x = 6x2, the 3 and 2 are multiplied, not added.
Method. Write everything as a power of 2, then add the indices.
- Write 4 as a power of 2. 4 = 2 × 2 = 22.4n = (22)n
- Use the power of a power law. Multiply the indices.(22)n = 22n
- Multiply the two powers of 2. Add the indices.22n × 2n+1 = 22n+n+1 = 23n+1
Check. Try n = 3: 43 × 24 = 64 × 16 = 1024 and 210 = 1024. ✓
Watch out. You can only use the index laws when the bases are the same, so change 4 into 22 first.