(3/5 x 6 2/9) + ( 3 3/4 : 5/12 )
(3/5 x 56/9) + ( 15/4 x 12/5)
56/15 + 9
3 11/15 + 9
12 11/15

(4 4/5 : 3 1/8) + ( 6 1/4 x 3 1/5)
( 24/5 : 25/8) + ( 25/4 x 16/5)
(24/5 x 8/25) + ( 4/1)
192/125 + 4
1 67/125 + 4
5 67/125

(15 5/8 : 2 1/12) – ( 2 1/7 x 3 3/10)

(125/8 : 25/12) – ( 15/7 x 33/10)
(125/8 x 12/25) – ( 495/70)
15/2 – 495/70
525/70 -495/70
30/70
3/7