x/x^2-x+1=1/5
即有(x^2-x+1)/x=5
x-1+1/x=5
x+1/x=6
(x+1/x)^2=x^2+2+1/x^2=36
x^2+1/x^2=34
x^2/x^4+x^2+1的值
=1/(x^2+1/x^2+1)
=1/(34+1)
=1/35