求帮忙解方程x³﹢2x-12=0

求帮忙解方程x³﹢2x-12=0
求帮忙解方程x³﹢2x-12=0

求帮忙解方程x³﹢2x-12=0
x^3+2x-12
=x^3+2x-4-8
=(2x-4)+(x^3-8)
=2(x-2)+(x-2)(x^2+2x+4)
=(x-2)(x^2+2x+6)
由于：x^2+2x+6恒大于0,
所以x-2=0
即：x=2

x³﹢2x-12=0
x³-2x²+2x²-4x+6x-12=0
x²(x-2)+2x(x-2)+6(x-2)=0
(x-2)(x²+2x+6)=0
所以
x=2

x³﹢2x-12=0；
x³-8+2x-4=0;
(x-2)(x²+2x+4)+2(x-2)=0;
(x-2)(x²+2x+6)=0
x=2;

X^3-4X+6X-12=0
X(X^2-4)+6(X-2)=0
X(X+2)(X-2)+6(X-2)=0
(X-2)(X(X+2)+6)=0
(X-2)((X+1)^2+5)=0
X=2