5/7+ 3 целых 6/7= 1 целая 6/11 - 7/11= 9/15+7/15= 9 целых- 3 целых 7/8= 6 целых 6/13 - 5 целых 11/13= 2 целых 15/19+

5/7 + 3 6/7 = 5/7 + (3 * 7 + 6)/7 = 5/7 + 27/7 = 32/7;

1 6/11 - 7/11 = 17/11 - 7/11 = 10/11;

9/15 + 7/15 = (9 + 7)/5 = 16/5;

9 - 3 7/8 = 9 - (3 * 8 + 7)/8 = 72/8 - 31/8 = 41/8;

6 6/13 - 5 11/13 = (6 * 13 + 6)/13 - (5 * 13 + 11)/13 = 84/13 - 76/13 = 8/13;

2 15/19 + 1 5/19 = (2 * 19 + 15)/19 + (1 * 19 + 5)/19 = 53/19 + 24/19 = 77/19;

1 5/7 - 6/7 = 12/7 - 6/7 = 6/7;

19/21 + 9/21 = 28/21 = 4/3;

9 1/7 - 2 5/7 = 64/7 - 19/7 = 45/7;

6 8/9 + 7 5/9 = 62/9 + 68/9 = 130/9;

6/7 + 5/7 = 11/7;

5 3/8 - 3 = 43/8 - 24/8 = 19/8;

7 9/17 + 8 8/17 = 128/17 + 144/17 = 272/17 = 16;

9 3/13 - 8 9/13 = 120/13 - 113/13 = 7/13;

1 6/11 - 7/11 = 17/11 - 7/11 = 10/11.