Ответ:

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

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

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

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

/- это дробь