1. 6 13/9 = 7 4/9
2. 66/13 - 44/13 = 22/13 = 1 9/13
3. 7 2/15 - 8/15 + 12/15 = 107/15 - 20/15 = 87/15 = 5 12/15
Задача
1) 5 3/12 - 2 8/12 = 63/12 - 32/12 = 31/12 = 2 7/12 - во второй день
2) 5 3/12 + 1 11/12 = 6 14/12 = 7 2/12 - в третий день.
3) 5 3/12 + 2 7/12 + 7 2/12 = 14 12/12 =15 ( ч)