Odpowiedź:
3/7 + 1/7 = 4/7
4/5 + 3/5 = 7/5 = 1 i 2/5
2 i 4/7 + 2/7 = 2 i 6/7
3 i 7/8 + 2 i 5/8 = 5 i 12/8 = 6 i 4/8 = 6 i 1/2
16/17 - 11/17 = 5/17
4 i 15/23 - 2 i 8/23 = 2 i 7/23
7 - 6/7 = 6 i 7/7 - 6/7 = 6 i 1/7
5 i 3/6 - 2 i 5/6 = 4 i 9/6 - 2 i 5/6 = 2 i 4/6 = 2 i 2/3
