x³-4x²-4x-5
问题描述：
x³-4x²-4x-5
答
x³-4x²-4x-5
=x³-1-4x²-4x-4
=(x-1)(x²+x+1)-4(x²+x+1)
=(x²+x+1)(x-1-4)
=(x²+x+1)(x-5)