应该型带是分山租梁解因式x³+x²-x-1=x³-x+x²逗运-1=x(x²-1)+x²-1=(x²-1)(x+1)=(x+1)(x-1)(x+1)=(x+1)²(x-1)
x³+x²-x-1=x²斗基野梁(x+1)-(x+1)=(x+1)(x²空脊谨-1)=(x+1)(x+1)(x-1)=(x+1)²(x-1)