Question

How do you factor completely `w^2 - w^2 y^4`?

Answer 1

`w^2(1+y)(1-y)(1+y^2)`

Explanation:

This is just a difference of squares. When you have `a^2 - b^2`, it's is equal to `(a+b)(a-b)`. Just simply expand it to see why. In this case, it would be

`(w)^2 - (w*y^2)^2`

`(w- wy^2)(w + wy^2)`

`w^2(1-y^2)(1+y^2)`

`w^2(1+y)(1-y)(1+y^2)`