X^3-3X-2=0X^3-X-2X-2=0X(X^2-1)-2(X+1)=0X(X+1)(X-1)-2(X+1)=0(X+1)(X^2-X-2)=0(X+1)(X-2)(X+1)=0(X+1)^2(X-2)=0
哥子明天来学校我教你…OK?
x^3+(x^2-x^2)-3x-2=0(x^3+x^2)-x^2-3x-2=0x^2(x+1)-(x+2)(x+1)=0(x+1)(x^2-x-2)=0(x+1)(x-2)(x+1)=0(x-2)(x+1)^2=0