问题 解答题
计算:
(1)
x-2
x+3
x2-9
x2-4

(2)
3
x-4
-
24
x2-16

(3)
1
2x
-
1
x+y
•(
x+y
2x
-x-y)
答案

(1)原式=

x-2
x+3
(x+3)(x-3)
(x+2)(x-2)

=

x-3
x+2

(2)原式=

3
x-4
-
24
(x+4)(x-4)

=

3(x+4)-24
(x+4)(x-4)

=

3x-12
(x+4)(x-4)

=

3
x+4

(3)原式=

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

=

1
2x
-
1-2x
2x

=

1-1+2x
2x

=1.

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