x^2/x^4+x^2+1=1/x^2+x^2+1x+1/x=3(x+1/x)^2=3^2=9x^2+1/x^2+2=9x^2+1/x^2=7则x^2+1/x^2+1=8即x^2/x^4+x^2+1=8
