Ответ:

Пошаговое объяснение:

7/12 + 4/15 = (35+16) / 60 = 51/60 = 17/20

17/20 : 51/60 = 17/20 * 60/51 = 1

1 * 27/34 = 27/34

2/5 - 1/6 = (12 - 5) / 30 = 7/30

7/30 : 49/60 = 7/30 * 60/49 = 2/7

27/34 : 2/7 = 27/34 * 7/2 = 189/68 = 2 53/68