x^3-3x^2+2=0变形为：x(x^2-3x+2)+2-2x=0x(x-2)(x-1)-2(x-1)=0(x-1)(x^2-2x-2)=0这样你就会算结果了吧.
x^3-3x+2=0可化为(X-1)^2(X+2)=0推出X-1=0或X=-2
