问题 填空题
计算:
1
x-1
-
2
x2-1
=______.
答案

原式=

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

单项选择题
单项选择题 A1型题