Respuesta :
(x-1)(x-1)(x-1)
(x^2-x-x+1)(x-1)
(x^2-2x+1)(x-1)
2x^2-2x+x-1+2x-x^2
2x^2 +x-1-x^2
(x^2-x-x+1)(x-1)
(x^2-2x+1)(x-1)
2x^2-2x+x-1+2x-x^2
2x^2 +x-1-x^2