7/9 + 15/ 15
5/6 - 3/8
3/5 - 1/3
31/21 - 3/14
3/4 + 3/10
6/7 + 8/3
3/4 + 2/5 + 1/6
3/5 + 3/15 - 3/10
15/30
41/45
4/15
11/24
74/21
53/42
79/60
21/20
