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