Thread: Simplifying this expression

(5x - y)^2 - (x - 5y)^2 / -4x - 4y

Here's what I got so far:
5x^2 - 2xy + y^2 - x^2 + 10xy + 5y^2 / -4x - 4y

and then

4x^2 + 8xy + 6y^2 / -4x - 4y

What do I do now?

1) Add parentheses so it says what you mean.

2 + 3 / 5 is NOT the same as (2+3)/5

2) Factor, Factor, Factor

4x^2 + 8xy + 6y^2 = 2(2x^2 + 4xy + 3y^2) -- For example