Answer
$x^3+y^3$
Work Step by Step
$$(x+y)(x^2-xy+y^2)$$ To multiply a binomial with a trinomial, multiply each term in the binomial by each term in the trinomial: $$=(x\times x^2)+[x\times (-xy)]+(x\times y^2)+(y\times x^2)+[y\times (-xy)]+(y\times y^2)$$ $$=x^3-x^2y+xy^2+x^2y-xy^2+y^3$$ Combine like terms: $$x^3+y^3$$
