问题 解答题
已知
x2
x2-2
=
1
1-
3
-
2
.求(
1
1-x
-
1
1+x
)÷(
x
x2-1
+x
)的值.
答案

1
1-x
-
1
1+x
)÷(
x
x2-1
+x)

=-

2x
(1-x)(1+x)
÷
x3
(1-x)(1+x)

=-

2x
(1-x)(1+x)
(1-x)(1+x)
x3
=-
2
x2

x2
x2-2
=
1
1-
2
-
3

x2-2
x2
=1-
2
-
3

即-

2
x2
=-(
2
+
3

∴原式=-(

2
+
3
).

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