问题 选择题
当x≠-1时,对于分式
1
x-1
总有(  )
A.
1
x-1
=
2
x+1
B.
1
x-1
=
x+1
x2-1
C.
1
x-1
=
x-1
x2-1
D.
1
x-1
=
-1
x-3
答案

1
x-1
=
1•(x+1)
(x-1)(x+1)
=
x+1
x2-1

故选:B.

单项选择题
单项选择题