How do you factor #ab + ac - 4b - 4c#?

1 Answer
Nov 27, 2015

Answer:

#color(blue)((a-4)(b+c)# is the factorised form of the expression.

Explanation:

#ab +ac -4b-4c#

We can make groups of two to factorise this expression:

#color(blue)((ab +ac)) color(green)((-4b-4c)#

#a# is common to both the terms in the first group, and #-4# is common to both the terms in the second group.

#=color(blue)(a)(b +c) color(green)(-4)(b+c)#

The term #(b+c)# is common to both the terms:

#color(blue)((a-4)(b+c)# is the factorised form of the expression.