问题
解答题
先化简,再求值:
|
答案
原式=
-1 x+1
•1 (x+1)(x-1) (x-1)2 x+1
=
-1 x+1 x-1 (x+1)2
=(x+1)-(x-1) (x+1)2
=
,2 (x+1)2
当x=
-1时,原式=3
=2 (
-1+1)23
.2 3
先化简,再求值:
|
原式=
-1 x+1
•1 (x+1)(x-1) (x-1)2 x+1
=
-1 x+1 x-1 (x+1)2
=(x+1)-(x-1) (x+1)2
=
,2 (x+1)2
当x=
-1时,原式=3
=2 (
-1+1)23
.2 3