7/9 - 2/9 =
2/3 + 3/6 =
12/9 - 2/3 =
22/8 - 20/8 =
3/8 + 5/4 =
1/3 + 2/4 =
3/5 + 4/5 =
10/12
5/9
6/9
2/8
7/5
13/8
7/6