Пошаговое объяснение:

№238

1) 1 4/9 + 3 2/7 = 1 28/63 + 3 18/63 = 4 46/63

2) 7 5/12 + 1 3/8 = 7 10/24 + 1 9/24 = 8 19/24

3) 8 7/20 + 4 19/30 = 8 21/60 + 4 38/60 = 12 59/60

4) 7 2/25 + 1 7/15 = 7 6/25 + 1 35/75 = 8 41/75

№245

1) 4 7/10 + 2 4/5 = 4 7/10 + 2 8/10 = 6 15/10 = 7 5/10 = 7 1/2

2) 5 3/5 + 7 5/6 = 5 18/30 + 7 25/30 = 12 43/30 = 13 13/30

3) 7 9/14 + 1 16/21 = 7 27/42 + 1 32/42 = 8 59/42 = 9 17/42

4) 5 7/8 + 9 11/20 = 5 70/80 + 9 44/80 = 14 114/80 = 15 34/80 = 15 17/40