5 цел. 6/7-3 цел 1/14

2 цел. 3/10-1 цел. 7/15

10-2 цел. 2/9

5 6/7 - 3 1/14 = 5 - 3 + (6/7 - 1/14) = 2 + (12/14 - 1/14) = 2 + 11/14 = 2 11/14

2 3/10 - 1 7/15 = 1 13/10 - 1 7/15 = 13/10 - 7/15 = 39/30 - 14/30 = 25/30 = 5/6

10 - 2 2/9 = 9 9/9 - 2 2/9 = 9 - 2 + (9/9 - 2/9) = 7 + 7/9 = 7 7/9