问题 填空题
当x=
2
时,
x+1
+
x-1
x+1
-
x-1
的值为______.
答案

当x=

2
时,

x+1
+
x-1
x+1
-
x-1

=

(
x+1
+
x-1
)2
((
x+1
-
x-1
)(
x+1
+
x-1
)

=

2x+2
x2-1
2

=x+

x2-1

=

2
+
2-1

=1+

2

故答案为:1+

2

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