已知x/x2-x+1=7,则x2x4+x2+1= _ .

问题描述:

已知

x
x2-x+1
=7,则
x2
x4+x2+1
= ___ .

由题意得:

x2-x+1
x
=
1
7
,即x+
1
x
=
8
7

x4+x2+1
x2
=x2+
1
x2
+1=(x+
1
x
)
2
-2+1=
15
49

其倒数
x2
x4+x2+1
=
49
15

故答案为:
49
15