1. 3 целых 1/4+2 целых 3/5= 3 целых 2/12+ 2 целых 2/12 = 5 целых 4/12
2. 5 цулых 1/6 : 31 = 31/6 * 1/31 = 1/6
3. 5 целых 4/12 : 2 целых 3/5 = 64/12 * 5/13 = 320/156 = 2 целых 2/39
4. 2/3 : 4/9 = 2/3 * 9/4 = 3/2 = 1 целая 1/2
5. 1/6 + 2 целые 2/39 = 1/6 + 80/39 = 1 + 160/78 = 3 целых 2/39
6. 3 целых 2/39 - 1 целая 1/2 = 119/39 - 3/2 = 238/78 - 117/78 = 121/78= 1 целая 43/78