x的三次方-4x的平方+4x-1

问题描述:

x的三次方-4x的平方+4x-1

我儿子没空,我来吧
原式=(x³-1)-(4x²-4x)
=(x-1)(x²+x+1)-4x(x-1)
=(x-1)(x²+x+1-4x)
=(x-1)(x²-3x+1)