先化简后求值: 3+x x-2 ÷(x+2- 5 x-2 ) ,其中x=2008

先化简后求值: 3+x x-2 ÷(x+2- 5 x-2 ) ,其中x=2008.
2025-05-08 13:42:09
推荐回答(1个)
回答1:

3+x
x-2
÷(x+2-
5
x-2
)

=
x+3
x-2
÷
x 2 -4-5
x-2

=
x+3
x-2
×
x-2
(x+3)(x-3)

=
1
x-3

当x=2008时,原式=
1
2008-3
=
1
2005