I have the following problem. I've tried working it. Am I correct?
ya^2-yb^2+xb^2-xa^2
y(a^2-b^2)+ x(b^2-a^2)
y(a+b)(a-b)+ x(b+a)(b-a)
(a+b)* (y(a-b)+ x(b-a))
-(a+b)(a-b)(y+