问题
解答题
先化简,再求值:
|
答案
原式=
÷(x2-2x x2-1
-2x-1 x+1
)x2-1 x+1
=
×x2-2x x2-1 x+1 2x-x2
=-
,1 x-1
当x=
+1时,原式=-2
=-1 x-1
=-1
+1-12
.2 2
先化简,再求值:
|
原式=
÷(x2-2x x2-1
-2x-1 x+1
)x2-1 x+1
=
×x2-2x x2-1 x+1 2x-x2
=-
,1 x-1
当x=
+1时,原式=-2
=-1 x-1
=-1
+1-12
.2 2