配方: X^3+3X^2-4X-X+1
=X(X^2+3X-4)-(X-1)
=X(X-1)(X+4)-(X-1)
=(X-1)(X^2+4X-1)
x^3+3x^2-5x+1=x(x^2+2x^2-3)+(x^2-2x+1)
=x(x+3)(x-1)+(x-1)^2
=(x-1)(x^2+4x-1)
-5x=-x-4x
那么可以化成
x^3-x+3x^2-4x+1
=(x^2+x)(x-1)+(x-1)(3x-1)
=(x-1)(x^2+4x-1)
x^3+3x^2-5x+1=(x-1)(x^2+4x-1)
回答的人竟然如此之多,而且都是对的,看来没什么必要和他们争了。