# How do you factor #ab^2-ab-72a#?

##### 1 Answer

Oct 3, 2015

Separate out the common factor

#ab^2-ab-72a = a(b-9)(b+8)#

#### Explanation:

First notice that all the terms are multiple of

#ab^2-ab-72a = a(b^2-b-72)#

Turning our attention to

There are several quick ways to find the pair

One way is to notice that

Anyway, we can deduce that

#ab^2-ab-72a = a(b-9)(b+8)#