x²-6x+1=0等式两边同除以xx-6+1/x=0x+1/x=6x²/(x^4+x²+1)=1/(x²+1+1/x²)=1/(x²+2+1/x²-1)=1/[(x+1/x)²-1]=1/(36-1)=1/35
要对x是否=-1/6进行讨论吧
x*x-6x+1=0，x-6+1/x=0,x+1/x=61/x²+x²+1=(x+1/x)²-2+1=6²-1=35
