Вычислите: 1) 3/8+1/3, 2) 4 целых 3/16+5 целых 5/12 3) 3 целых 9/14+ 4 целых 33/40- 3 целых 19 30

1)
3/8 + 1/3 = 9/24 + 8/24 = 17/24,
2)
4 3/16 + 5 5/12 = (4 + 5) + (3/16 + 5/12) = 9 + (9/48 + 20/48) = 9 29/48, 
3)
3 9/14 + 4 33/40 - 3 19/30 = (3 + 4 - 3) + (9/14 + 33/40 - 19/30) = 4 + (540/840 + 693/840 - 532/840) = 4 + 701/840 = 4 701/840