问题
解答题
先化简,再求值:(x-
|
答案
原式=(
-x2+x x+1
)÷x+4 x+1 (x-2)2 x+1
=
•x2-4 x+1 x+1 (x-2)2
=(x+2)(x-2) (x-2)2
=
,x+2 x-2
当x=-1时,原式=
=--1+2 -1-2
.1 3
先化简,再求值:(x-
|
原式=(
-x2+x x+1
)÷x+4 x+1 (x-2)2 x+1
=
•x2-4 x+1 x+1 (x-2)2
=(x+2)(x-2) (x-2)2
=
,x+2 x-2
当x=-1时,原式=
=--1+2 -1-2
.1 3