问题 解答题
计算:
(1)(
1
a
-
1
b
a-b
ab

(2)(
x-2
x+2
+
4x
x2-4
)÷
1
x2-4
答案

(1)原式=

b-a
ab
×
ab
a-b

=-1;

(2)[

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

=(x-2)2+4x

=x2-4x+4+4x

=x2+4.

判断题
判断题