Решить 15/19 -7/19+4/19,7 целых 5/14 +3 целых 11/14 ,5-2 целых 4/11 , и 8 целых 2/9 - 2 целых 4/9 .

15/19 - 7/19 + 4/19 = (15-7+4)/19 = 12/19
7 5/14 + 3 11/14 = (7+3) + (5+11)/14 = 10 + 16/14 = 11 1/7
5 - 2 7/11 = (55-29)/11 = 26/11 = 2 4/11
8 2/9 - 2 4/9 = 7 (9+2)/9  - 2 4/9 = (7-2) (11-4)/9 = 5 7/9 
Проверено