1)
3/5*4/9 + 1 1/3 =
12/45 + 4/3 = 12/45 + 60/45 = 72/45 = 1 27/45 = 1 3/5 = 1,6
2)
3/8:1/2 + 3 1/4 =
3/8*2/1 + 13/4 = 6/8 + 13/4 = 6/8 + 26/8 = 32/8 = 4
3)
1 2/5:5/7 + 3/8 =
7/5:5/7+3/8 = 7/5*7/5+3/8 = 49/25 + 3/8 = 392/200 + 75/200 = 467/200 = 2 67/200 = 2,335