Question

como multiplico?

a)x-y . x+y

b) 2y . x-y

Answer 1

$\boxed{a) \ (x-y)(x+y)=x^2+xy-xy-y^2=x^2-y^2}\\ \\ \boxed{b) \ 2y(x-y)=2xy-2y^2}$

Answer 2

a) (x-y) .(x+y ) = x² - y²

b) 2y .( x-y )  ==> 2xy - 2y²