问题 解答题
先化简,再求值:
x2
x-1
÷(1+
1
x2-1
)
,其中x=2008.
答案

x2
x-1
÷(1+
1
x2-1
)

=

x2
x-1
÷
x2-1+1
x2-1

=

x2
x-1
(x+1)(x-1)
x2

=x+1(6分)

当x=2008时,原式=2009.(8分)

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