Помогите! упростить 2х(х-4)-(х+
2x(x - 4) - (x + 5)^2 = 2x^2 - 8x - (x^2 + 10x + 25) = = 2x^2 - 8x - x^2 - 10x - 25 = = x^2 - 18x - 25