问题 解答题
计算:
x
x2-4
-
1
2x-4
答案

x
x2-4
-
1
2x-4

=

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

=

2x
2(x-2)(x+2)
-
x+2
2(x-2)(x+2)
(2分)

=

x-2
2(x+2)(x-2)
(4分)

=

1
2(x+2)
(或
1
2x+4
)(5分)

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