解
1、x/(x^2-x+1)=7
7x^2-8x+7=0
(7x-1)(x-7)=0
x=1/7,或x=7
2、当x=1/7时,x^2/(x^4+x^2+1 )=(1/7)^2/【(1/7)^4+(1/7)^2+1 )】=49/99
当x=7时,x^2/(x^4+x^2+1 )=(7)^2/(7^4+7^2+1)=2451/49
解
1、x/(x^2-x+1)=7
7x^2-8x+7=0
(7x-1)(x-7)=0
x=1/7,或x=7
2、当x=1/7时,x^2/(x^4+x^2+1 )=(1/7)^2/【(1/7)^4+(1/7)^2+1 )】=49/99
当x=7时,x^2/(x^4+x^2+1 )=(7)^2/(7^4+7^2+1)=2451/49