Question

64- Mostre que=
$(x + y).( {x}^{2} - xy + {y}^{2}) = {x}^{3} + {y}^{3}$

Answer 1

$(x+y)(x^2-xy+y^2=x^3+y^3 \\ \\ x^3-x^2y+xy^2+x^2y-xy^2+y^3=x^3+y^3 \\ \\ x^3-\not x^2y+\not x^2y+\not xy^2-\not xy^2+y^3=x^3+y^3 \\ \\ x^3+y^3=x^3+y^3$