Сократите дробь (x^3-y^3)(x+y) --------------------- = x^2-y^2
(x^3-y^3)(x+y) --------------------- = x^2-y^2 (x-y)(x^2+xy+y^2)(x+y)/(x-y)(x+y)=x^2+xy+x^2
спасибо