问题
解答题
先化简,再求值:
|
答案
•2x+6 x2-4x+4
-x-2 x2+3x 1 x-2
=
•2(x+3) (x-2)2
-x-2 x(x+3) 1 x-2
=
-2 x(x-2) 1 x-2
=2-x x(x-2)
=-
;1 x
当x=-
时,2
原式=
=1 2
.2 2
先化简,再求值:
|
•2x+6 x2-4x+4
-x-2 x2+3x 1 x-2
=
•2(x+3) (x-2)2
-x-2 x(x+3) 1 x-2
=
-2 x(x-2) 1 x-2
=2-x x(x-2)
=-
;1 x
当x=-
时,2
原式=
=1 2
.2 2