问题 解答题
计算
(1)
2a
a2-4
-
1
a-2

(2)(
2x
x-3
-
x
x+3
)•
x2-9
x
答案

(1)原式=

2a
(a+2)(a-2)
-
a+2
(a+2)(a-2)

=

2a-a-2
(a+2)(a-2)
=
a-2
(a+2)(a-2)

=

1
a+2

(2)原式=

2x
x-3
x2-9
x
-
x
x+3
x2-9
x

=2(x+3)-(x-3)=x+9.

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