Question

计算 1.(-2x)^3-3x乘（x-2x^2） 2.【(x+2y)^2-(x-2y)（x+2y）】÷4y

Answer 1

(1)

(-2x)^3-3x乘（x-2x^2）

=-8x³-3x²+6x³

=-2x³-3x²

=-x²(2x+3)

(2)

[(x+2y)^2-(x-2y)(x+2y)]÷4y

=(x²+2xy+4y²-x²+4y²)/4y

=(2xy+8y²)/4y

=(x+4y)/2