Odpowiedź:
6/8 - 1/5 = 30/40 - 8/40 = 22/40 = 11/20
2/3 - 2/4 = 8/12 - 6/12 = 2/12 = 1/6
4/7 - 1/2 = 8/14 - 7/14 = 1/14
4/9 - 5/12 = 16/36 - 15/36 = 1/36
5/6 - 5/9 = 15/18 - 10/18 = 5/18
17/21 - 3/14 = 34/42 - 9/42 = 25/42
5/6 - 4/15 = 25/30 - 8/30 = 17/30
5 i 2/3 - 2 i 1/4 = 5 i 8/12 - 2 i 3/12 = 3 i 5/12
4 i 3/10 - 2 i 1/5 = 4 i 3/10 - 2 i 2/10 = 2 i 1/10
7 i 3/4 - 5 i 1/3 = 7 i 9/12 - 5 i 4/12 = 2 i 5/12
4 i 5/7 - 1 i 1/2 = 4 i 10/14 - 1 i 7/14 = 3 i 3/14
2 i 3/7 - 2/5 = 2 i 15/35 - 14/35 = 2 i 1/35
