问题
解答题
已知x=3-
|
答案
(
-x+3 x2-3x
)÷x-1 x2-6x+9 x-9 x
=[
-x+3 x(x-3)
]•x-1 (x-3)2 x x-9
=[
-(x+3)(x-3) x(x-3)2
]•(x-1)x x(x-3)2 x x-9
=
•x2-9-x2+x x(x-3)2 x x-9
=1 (x-3)2
当x=3-
时,2
原式
=1 (3-
-3)22
.1 2