# How do you factor #12r^2 - 7r - 12# by grouping?

##### 1 Answer

Aug 18, 2016

#### Explanation:

We need to find how to split the middle term. To do that, use an AC method:

Look for a pair of factors of

The pair

#12r^2-7r-12#

#=12r^2-16r+9r-12#

#=(12r^2-16r)+(9r-12)#

#=4r(3r-4)+3(3r-4)#

#=(4r-3)(3r-4)#