# Math Help - Factoring polynomial help please

1. ## Factoring polynomial help please

Here it is.

ab+2b-4a-8

Thanks

the answer given is (a+2)(b-4) but not sure how to get it.

2. Originally Posted by MathMack
Here it is.

ab+2b-4a-8

Thanks

the answer given is (a+2)(b-4) but not sure how to get it.
Factor out b, out of the first two terms.
Factor out -4 out of the last two terms.

$b(a + 2) - 4(a + 2)$

$= (b - 4)(a + 2)$