问题 解答题
化简:
(1)(
-a
b
)2÷(
2a2
5b
)2
a
5b

(2)(
x+2
x2-2x
-
x-1
x2-4x+4
x-4
x
答案

(1)原式=

a2
b2
25b2
4a4
a
5b

=

5
4ab

(2)原式=[

x+2
x(x-2)
-
x-1
(x-2)2
]•
x
x-4

=[

(x+2)(x-2)
x(x-2)2
-
x(x-1)
x(x-2)2
]•
x
x-4

=

x-4
x(x-2)2
x
x-4

=

1
x2-4x+4

单项选择题
单项选择题 A1型题