7/12 + 2/12 =
5/6 + 4/6 =
8/5
5/9 + 11/9 =
16/9
17/10 - 9/10 =
5/14
9/6
11/5 - 3/5 =
9/12
8/10
7/11
7/14 -2/14 =
9/11 - 2/11=
