Respuesta :

(5x^2 + x - 4)(x + 2) = x(5x^2 + x - 4) + 2(5x^2 + x - 4) = 5x^3 + x^2 - 4x + 10x^2 + 2x - 8 = 5x^3 + 11x^2 - 2x - 8