Distributive property, step by step
Multiplying out a bracket means the number outside reaches everything inside it, not just the first thing.
The question
Multiply out the bracket.
3(4 + 4x)
3(4 + 4x)
3 × 4=12
3 × 4x=12x
12x+12
- The 3 outside multiplies EVERYTHING inside the bracket, not just the thing next to it. Draw an arrow from the 3 to each of the two terms before working anything out — that is what stops one of them being left behind.
- First arrow: 3 × 4 = 12.
- Second arrow: 3 × 4x = 12x.
- Put the two together: 12x + 12. Check it by putting a small number in for x on both forms — they should agree, because they are the same amount written two ways.
How it works.
- 01
The 3 outside multiplies EVERYTHING inside the bracket, not just the thing next to it. Draw an arrow from the 3 to each of the two terms before working anything out — that is what stops one of them being left behind.
- 02
First arrow: 3 × 4 = 12.
- 03
Second arrow: 3 × 4x = 12x.
- 04
Put the two together: 12x + 12. Check it by putting a small number in for x on both forms — they should agree, because they are the same amount written two ways.