\(\left(x^2-xy+y^2\right)\left(x+y\right)=x^3+y^3\)
\(\left(x^2-xy+y^2\right)\left(x+y\right)=x^3+y^3\)
\(\left(x+y\right)\left(x^2-xy+y^2\right)=x^3+y^3\)
(x2- xy+y2)(x+y)=(x-y)2(x+y)=(x-y)(x2-y2)=x3-xy2-x2y+y3
(x2- xy+y2)(x+y)
= x3 +x2y - x2y - xy2 + xy2 + y3
= x3 + y3
\(\left(x^2-xy+y^2\right)\left(x+y\right)\\ =x\cdot\left(x^2-xy+x^2\right)+y\cdot\left(x^2-xy+y^2\right)\\ =x^2x+\left(-xy\right)\cdot x+y^2x+x^2y+\left(-xy\right)\cdot y+y^2y\\ =x^3-x^2y+xy^2+x^2y-xy^2+y^3\\ =x^3+y^3+\left(xy^2-xy^2\right)+\left(xy^2-xy^2\right)\\ =x^3+y^3\)