Пошаговое объяснение:

х - 2/3 = 1/5

х = 1/5 + 2/3

х = 3/15 + 10/15

х = 13/15

4/5 - х = 2/15

х = 4/5 - 2/15

х = 12/15 - 2/15

х = 10/15

х = 2/3

2/9 + х = 5/6

х = 5/6 - 2/9

х = 15/18 - 4/18

х = 11/18