(42 5/7 - 4 2/3) - (23 - 15 9/14) = 30 29/42
1) 42 5/7 - 4 2/3 = 42 15/21 - 4 14/21 = 38 1/21
2) 23 - 15 9/14 = 22 14/14 - 15 9/14 = 7 5/14
3) 38 1/21 - 7 5/14 = 38 2/42 - 7 15/42 = 37 44/42 - 7 15/42 = 30 29/42
ответ: 30 целых 29/42.
(42 5/7 - 4 2/3) - (23 - 15 9/14) = 30 29/42
1) 42 5/7 - 4 2/3 = 42 15/21 - 4 14/21 = 38 1/21
2) 23 - 15 9/14 = 22 14/14 - 15 9/14 = 7 5/14
3) 38 1/21 - 7 5/14 = 38 2/42 - 7 15/42 = 37 44/42 - 7 15/42 = 30 29/42
ответ: 30 целых 29/42.