问题 解答题
先化简式子
x-3
x2-1
÷
x
x+1
-
1
x-1
,然后从-2<x≤2中选择一个合适的整数x代入求值.
答案

原式=

x-3
(x-1)(x+1)
x+1
x
-
1
x-1

=

x-3
x(x-1)
-
1
x-1

=

x-3
x(x-1)
-
x
x(x-1)

=-

3
x(x-1)

=-

3
x2-x

∵-2<x≤2且x为整数,

∴x=-1,0,1,2

∵x(x-1)(x+1)≠0,

∴x≠0且x≠±1,

∴x=2

当x=2时,原式=-

3
22-2
=-
3
2

默写题
问答题 简答题