Question

How do you expand `2(4b-5)-4b`?

Answer 1

`4b-10` is the answer, however, some teachers prefer the answer to be factored. We can factor a 2 out and get a final answer of:
`=2(2b-5)`

Explanation:

`2(4b-5)-4b`

To expand, we use the distributive property first: `a(b+c)=ab+ac`

`=2(4b)-2(5)-4b`
`=8b-10-4b`

Combine like terms, meaning add terms which contain `b` to each other:
`=8b-4b-10`
`=4b-10`

`=2(2b-5)`