(x+y)(x2-xy+y2)-(x-y)(x2+xy+y2)=?

Question

(x+y)(x2-xy+y2)-(x-y)(x2+xy+y2)=?

Answer 1

(x+y)(x2-xy+y2)-(x-y)(x2+xy+y2)=x^3+y^3-(x^3-y^3)=x^3+y^3-x^3+y^3)=2*y^3