How do you factor completely x^2 - y^2 +xz - yz?

1 Answer
May 5, 2016

x^2-y^2+xz-yz=(x-y)(x+y+z)

Explanation:

x^2-y^2+xz-yz

=(x^2-y^2)+(xz-yz)

=(x-y)(x+y)+(x-y)z

=(x-y)((x+y)+z)

=(x-y)(x+y+z)

Note the step where we replace (x^2-y^2) with (x-y)(x+y)

The identity:

x^2-y^2=(x-y)(x+y)

is known as the difference of squares identity.