Алгебра помогите срочно

1)

2x(5x-6)+x(4x-7) = 10x^2 -12x +4x^2-7x = 14x^2 -19x

2)
ab(a-b)+(a-2b)ab = a^2b-ab^2 + a^2b-2ab^2 = 2ab^2-3ab^2

3)

10x-10y - 12x+9y = -2x-y

4)
-a(a^2+b^2 +2a^2-2b^2) = -3a^3+ab^2

5)

2xy(x^2-y-2y+x^2) = 2xy(2x^2-3y) = 2*(-1)*2*(2-6) = -4*-4=16