−x2−2x-x^2 - 2x−x2−2x^2 = −x2−2x-x^2 - 2x−x2−2x * −x2−2x-x^2 - 2x−x2−2x = x^4 + 2x^3 + 2x^3 + 4x^2= x^4 + 4x^3 + 4x^2
−x2−2x-x^2 - 2x−x2−2x^2 = −x2−2x-x^2 - 2x−x2−2x * −x2−2x-x^2 - 2x−x2−2x = x^4 + 2x^3 + 2x^3 + 4x^2
= x^4 + 4x^3 + 4x^2