问题 解答题
计算:
(1)
a2
a-b
-
b2
a-b
(2)
12
m2-9
+
2
3-m
答案

(1)原式=

a2-b2
a-b
=
(a+b)(a-b)
a-b
=a+b;

(2)原式=

12
(m+3)(m-3)
-
2
m-3

=

12-2(m+3)
(m+3)(m-3)

=

-2(m-3)
(m+3)(m-3)

=-

2
m+3

故答案为a+b、-

2
m+3

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