先化简 1 x+1 - 1 x 2 -1 ÷ x+1 x 2 -2x+1 ,然后从-1,1,2

2025-05-19 18:22:13
推荐回答(1个)
回答1:

原式=
1
x+1
-
1
(x+1)(x-1)
?
(x-1 ) 2
x+1

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

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

=
2
(x+1 ) 2

当x=2时,原式=
2
9