Ответ:

Пошаговое объяснение:

12 5/9 - 7 * 1/6 = 12 5/9 - 7/6 = 12 10/18 - 21/18 =

12 10/18 - 1 3/18 = 11 7/18

7*1/4 - 3*7/15 = 7/4 - 21/15 = 105/60 - 84/60 = 21/60 = 7/20

9*5/12 - 6*2/7 = 45/12 - 12/7 = 315/84 - 144/84 = 171/84 = 2 3/84 = 2 1/28