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