[2(x-1)^2+(x-1)^3]÷(1-x)

问题描述:

[2(x-1)^2+(x-1)^3]÷(1-x)

[2(x-1)^2+(x-1)^3]÷(1-x)
=[2(1-x)^2-(1-x)^3]÷(1-x)
=2(1-x)-(1-x)^2
=1-x^2