X立方-7X平方+4X+12=0
问题描述：
X立方-7X平方+4X+12=0
答
x^3-7x^2+4x+12=0
x^3-2x^2-5x^2+10x-6x+12=0
x^2(x-2)-5x(x-2)-6(x-2)=0
(x-2)(x^2-5x-6)=0
(x-2)(x-6)(x+1)=0
x=2或x=6或x=-1
答
x³-2x²-5x²+4x+12=0
x²(x-2)-(5x²-4x-12)=0
x²(x-2)-(5x+6)(x-2)=0
(x-2)(x²-5x-6)=0
(x-2)(x-6)(x+1)=0
x=2,x=6,x=-1