∵ x/(x²-x+1)=1/6
∴ (x²-x+1)/x=6
x²-x+1=6x
x²+1=7x
∵ (x²+1)×1/x=7x×1/x
x²×1/x+1×1/x=7
x+(1/x)=7
∴ [x+(1/x)]²=7²
x²+2×x×1/x+(1/x²)=49
x²+2+(1/x²)=49
∴ x²+(1/x²)=47
∵ (x^4+x²+1)/x²=(x^4/x²)+(1/x²)+(x²/x²) ( ^ 表示乘方 )
=x²+(1/x²)+1
=47+1
=48
∴ x²/(x^4+x²+1)=1/48