1) 2 целых 15/19 + 1 целая 5/19 = 53/19+24/19 = (53+24)/19 = 77/19 = 4 целых 1/19 2) 1 целая 5/7 - 6/7 = 12/7 - 6/7 =(12-6)/7 3) 19/21 + 9/21= (19+9)/21 = 1 целая 7/21 = 1 целая 1/3 4) 9 целых 1/7 - 2 целых 5/7 = 64/7 -19/7 = (64-19)/7 = 6 целых 3/7 5) 6 целых 8/9 + 7 целых 5/9= 62/9+68/9 = 130/9 = 14 целых 4/9 = 14 целых 2/3