求学霸解其中两题。可以只回答一个！！

①解：x-3-1/x=0x-1/x=3（x-1/x）²=9x²-2+1/x²=9x²+1/x²=11（x+1/x）²=x²+1/x²+2=11+2=13x4次方+1/x4次方=（x²+1/x²）²-2=11²-2=119最后一个你写的不是很明确

x^2-3x-1=0两边同时除以xx-3-1/x=0x-1/x=3两边平方（x-1/x)^2=9x^2-2+1/x^2=9x^2+1/x^2=11(x+1/x)^2=x^2+2+1/x^2=11+2=13x^4+1/x^4=(x^2+1/x^2)-2=11^2-2=121-2=119x^2/(x^4+x^2+1)=1/[(x^4+x^2+1)/x^2]=1/(x^2+1+1/x^2)=1/(11+1)=1/12