(7-2 2/5:8/15):5 5/8

(7 - 2 2/5 : 8/15) : 5 5/8 = 4/9

1) 2 2/5 : 8/15 = 12/5 · 15/8 = (3·3)/(1·2) = 9/2 = 4 1/2

2) 7 - 4 1/2 = 6 2/2 - 4 1/2 = 2 1/2

3) 2 1/2 : 5 5/8 = 5/2 : 45/8 = 5/2 · 8/45 = (1·4)/(1·9) = 4/9