设：x+1/x=y则：x^2+1/x^2=(x+1/x)^2-2=y^2-2X的三次方+X的负三次方=(x+1/x)(x^2+1/x^2-1)=y(y^2-3)=y^3-3y=2y^3-3y-2=0(y^3-2y^2)+(2y^2-4y)+(y-2)=0(y^2+2y+1)(y-2)=0(y-2)(y+1)^2=0y=2,或,y=-1即：X的一次方+X的...