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

希望能帮你忙,不懂请追问,懂了请采纳,谢谢