Помогите пожалуйста решить номер123(1,2)

1) (3а²-6а)(0,5а^4 -2) -5a²(0,3a^4 -1)+a²-12a = 1,5a^6 -6a² - 3a^5 + 12a  -1,5a^6 + 5a² + a² - 12a = -3a^5
2) (x³-y²)(2x^4 -y³) - (2x²-y)(x^5 -y^4) = 2x^7 -(xy)³ - 2(x²y)² + y^5 - 2x^7+ 2(xy²)² +yx^5-y^5 = -(xy)³ - 2(x²y)²  + 2(xy²)² +yx^5 = (yx²)(x³ -xy²+2y³-2x²y)=(yx²)(x(x²-y²)-2y(x²-y²)) = x²y(x-2y)(x²-y²)²