问题 解答题
化简:
(1)
x2
x-2
-
4x
x-2
+
4
x-2

(2)1-
a-1
a
÷(
a
a+2
-
1
a2+2a
)
答案

(1)原式=

x2-4x+4
x-2
=
(x-2)2
x-2
=x-2;

(2)原式=1-

a-1
a
÷
a2-1
a(a+2)
=1-
a-1
a
a(a+2)
(a+1)(a-1)
=1-
a+2
a+1
=-
1
a+1

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