Question

请学霸们帮忙，这几怎么做？这题是简便计算。

Answer 1

4-8/15-7/15
=4-(8/15+7/151
=4-1
=3

追答

7/12+5/17-7/12+12/17
=(7/12-7/12)+(5/ 17+12/17)
=0+1
=1

11/18-(11/18-7/23)
=11/18-11/18+7/23
=0+7/23
=7/23

1/2+(5/6-3/4)
=1/2+5/6-3/4
=3/6+5/6-3/4
=8/6-3/4
=4/3-3/4
=16/12-9/12
=7/12