问题 解答题
计算题:
(1)
5x+3y
x2-y2
-
2x
x2-y2

(2)
1
x+1
+
2
x2-1

(3)|-3|+(-1)2013×(π-3)-(-
1
2
-3
答案

(1)原式=

5x+3y-2x
x2-y2

=

3(x+y)
(x+y)(x-y)

=

3
x-y

(2)原式=

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

=

x+1
(x+1)(x-1)

=

1
x-1

(3)原式=3-1×(π-3)+8

=3-π+3+8

=14-π.

单项选择题
单项选择题