问题
解答题
先化简,再求值:(
|
答案
(
-2 x2-2x
)÷1 x2-4x+4 x-4 x
=(
-2 x( x-2)
)÷1 (x-2)2 x-4 x
=(
-2(x-2) x(x-2)2
)•x x(x-2)2 x x-4
=
•x-4 x(x-2)2 x x-4
=
,1 (x-2)2
当x=
时,原式=1 2
=1 (x-2)2
.4 9
先化简,再求值:(
|
(
-2 x2-2x
)÷1 x2-4x+4 x-4 x
=(
-2 x( x-2)
)÷1 (x-2)2 x-4 x
=(
-2(x-2) x(x-2)2
)•x x(x-2)2 x x-4
=
•x-4 x(x-2)2 x x-4
=
,1 (x-2)2
当x=
时,原式=1 2
=1 (x-2)2
.4 9