# How do you factor #9(x + 2y + z)^2 - 16(x - 2y + z)^2#?

##### 1 Answer

Jul 4, 2015

#### Answer:

This is a difference of squares.

#### Explanation:

Difference of squares:

#=[3(x+2y+z) + 4(x - 2y + z)] [3(x+2y+z) - 4(x - 2y + z)]#

Each of these factors can be simplified, to get: