先化简,再求值:1m-1m2?m?m2?2m+1m,其中m=3

先化简,再求值:1m-1m2?m?m2?2m+1m,其中m=3.
2025-05-06 17:17:59
推荐回答(1个)
回答1:

1
m
-
1
m(m?1)
?
(m?1)2
m

=
1
m
-
m?1
m2

=
1
m2

当m=
3
时,原式=
1
(
3
)2
=
1
3