Question

How do I solve 20? Thanks

Answer 1

20)

using
a^3 + b^3 = (a+b)(a^2 − ab + b^2)
so
w^3 + 125z^3
= w^3 +(5z)^3
= (w + 5z)(w^2 - 5wz + 25z^2)

hope it helps