Ответ:
- 12 + 8 = 20; 3/8 + 1/6 = 9/24 + 4/24 = 13/24. Итого 20 13/24.
- 8 + 6 = 14; 13/15 + 7/10 = 26/30 + 21/30 = 47/30 = 1 17/30. Итого 15 17/30.
- 9 + 4 = 13; 8/21 + 11/14 = 16/42 + 33/42 = 49/42 = 1 1/6. Итого 14 1/6.
- 8 + 7 + 12 = 27; 5/9 + 3/4 + 7/12 = 20/36 + 27/36 + 21/36 = 68/36 = 1 8/9. Итого 28 8/9.
