问题
解答题
计算 ①3
②先化简,再求值:求x+1-
|
答案
①原式=
+3-1+3
-23 3
=3-1
=2.
②原式=
-(x+1)(x-1) x-1 x2 x-1
=x2-1-x2 x-1
=-
;1 x-1
当x=
+1时,2
原式=-
=-1
+1-12
=-1 2
.2 2
计算 ①3
②先化简,再求值:求x+1-
|
①原式=
+3-1+3
-23 3
=3-1
=2.
②原式=
-(x+1)(x-1) x-1 x2 x-1
=x2-1-x2 x-1
=-
;1 x-1
当x=
+1时,2
原式=-
=-1
+1-12
=-1 2
.2 2