问题
解答题
先化简,再求值:(
|
答案
原式=(
-x x-2
)÷2(x-2) x-2 x2-16 x2-2x
=
÷x-2x+4 x-2 x2-42 x2-2x
=
•-x+4 x-2 x(x-2) (x+4)(x-4)
=
•-(x-4) x-2 x(x-2) (x+4)(x-4)
=-
,x x+4
当x=
-4时,原式=-3
=-x x+4
=
-43
-4+43
.4
-33 3