1)

4 1/5:7/15:1/3=

2)

4 1/5: (7/15:1/3) =

3)

(5 8/9:1 17/36+1 1/4) : 4 1/5=

4)

(2 1/4+4 5/6) : 3 2/5-3/4:3/5=

1) 21/5 * 15/7 * 3/1=9*3=27

2) 21/5 / (7/15*3/1) = 21/5*5/7=3

3) (53/9*36/53 + 5/4) : 21/5 = (4+5/4) : 21/5 = 21/4 * 5/21=5/4=1 1/4

4) (9/4+29/6) * 5/17 - 3/4 * 5/3 = 85/12*5/17-5/4=25/12-5/4 = 25-15/12=10/12=5/6