问题 解答题
计算:(1)
x+2
x2-6x+9
÷
1
3-x
×
x-3
x+2
      (2)(
x2-1
x2-2x+1
-x+1)÷
x
x-1
答案

(1)

x+2
x2-6x+9
÷
1
3-x
×
x-3
x+2

=

x+2
(x-3)2
×(3-x)×
x-3
x+2

=-1;

(2)(

x2-1
x2-2x+1
-x+1)÷
x
x-1

=[

(x-1)(x+1)
(x-1)2
-
(x-1)2
x-1
x-1
x

=

-x2+3x
x-1
×
x-1
x

=-x+3.

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