Question

How do you factor `-36x^2 + 36y^2`?

Answer 1

`-36x^2+36y^2= color(green)((-36)(x-y)(x+y))`

Explanation:

`-36x^2+36y^2`
`color(white)("XXX")=(-36)(x^2-y^2)`

`color(white)("XXX")=(-36)(x-y)(x+y)`

`(-36)` could be further factored as `(-1)(6^2)` or `(-1)(2^2*3^2)` but I'm not sure there is any point in doing this.