Question

Multiply the trinomial x^2+xy+y^2 times the binomial x-y and simplify.

Answer 1

Multiply then simplify, that's doing the same work twice...anyway

x^3+x^2y+xy^2-x^2y-xy^2-y^3

x^3-y^3  which if factored is:

(x-y)(x^2+xy+y^2)  which is what you started with :)