Question

х^3-y^3+5х(х^2+ху+у^2)

Answer 1

$x^3-y^3+5x(x^2+xy+y^2)= \ \ =(x-y)(x^2+xy+y^2)+5x(x^2+xy+y^2)= \ \ =(x^2+xy+y^2)(x-y+5x)= \ \ = (x^2+xy+y^2)(6x-y)$