1)
4 11/45 + (3 14/15 + 5 2/45) = 44/45 + (14/5 + 2/9) = 44/45 + 136/45 = 44 + 136/45 = 180/45 = 4
2)
7 43/50 + (2 31/50 + 4 17/25) = 301/50 + (31/25 + 68/25) = 301/50 + 99/25 = 301 + 198/50 = 499/50
3)
44 8/70 + (46 18/35 + 2 9/70) = 176/35 + ( 828/35 + 9/35) = 176/35 + 837/35 = 176 + 837/35 = 1013/35
4)
55 19/72 + (19 5/24 + 20 17/72) = 1045/72 + (95/24 + 85/18) = 1045/72 + 625/72 = 1045 + 625/72 = 1670/72 = 835/36