问题 解答题
先化简,再求值:
x2-2x
x2-1
÷(x-1-
2x-1
x+1
)
,选一个你喜欢的实数x代入求值.
答案

x2-2x
x2-1
÷(x-1-
2x-1
x+1
),

=

x(x-2)
(x+1)(x-1)
÷
x2-1-2x+1
x+1

=

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

=

1
x-1

当x=6时,原式=

1
6-1
=
1
5

选择题
单项选择题 A1/A2型题