问题 填空题
直接写出结果:
(1)
m-n
a
+
m+n
a
=______;
(2)
x2
x+y
-
y2
x+y
=______.
答案

(1)

m-n
a
+
m+n
a
=
m-n+m+n
a
=
2m
a

(2)

x2
x+y
-
y2
x+y
=
x2-y2
x+y
=
(x+y)(x-y)
x+y
=x-y.

单项选择题 A3/A4型题
单项选择题