原式可化为：x^4+2x^3-6x^2+2x-1=0
x^2(x^2+2x-3)-(3x^2-2x-1)=0
x^2(x+3)(x-1)-(3x+1)(x-1)=0
(x-1)(x^3+3x^2-3x-1)=0
(x-1)[(x^3+3x^2-4x)+(x--1)]=0
(x-1)[x(x+4)(x-1)+(x--1)]=0
(x-1)^2(x^2+4x+1)=0
(x-1)^2[x-(-2+√3)][x-(-2-√3)]=0
所以：x=1 x=-2+√3 x=-2-√3