2 1/6 и 3 1/9 = 2 3/18 u 3 2/18
4 2/7 и 5 4/21 = 4 6/21 u 5 4/21
1 3/11 и 2 1/2 = 1 6/22 u 2 11/22
2 8/15 и 1 5/12 = 2 32/60 u 1 25/60
2 1/6 и 3 1/9 = 2 3/18 u 3 2/18
4 2/7 и 5 4/21 = 4 6/21 u 5 4/21
1 3/11 и 2 1/2 = 1 6/22 u 2 11/22
2 8/15 и 1 5/12 = 2 32/60 u 1 25/60