(5/12-3/7)-(4/7-7/12)能简算就要简算

问题描述:

(5/12-3/7)-(4/7-7/12)能简算就要简算

最后得0啊......
5/12和7/12相加为1
-3/7和-4/7相加为-1

5/12-3/7-4/7+7/12
=(5+7)/12-(3+4)/7
=1-1=0

5/12-3/7-4/7+7/12
=5/12+7/12-(3/7+4/7)
=1-1
=0

=5/12-3/7-4/7+7/12
=(5/12+7/12)-(3/7+4/7)
=1-1
=0