3 целых 11/24-x=1 целая 1/6+1 целая 1/9

3 11/24 - х = 1 1/6 + 1 1/9

х = 3 11/24 - (1 1/6 + 1 1/9)

х = 3 33/72 - (1 12/72 + 1 8/72)

х = 3 33/72 - 2 20/72

х = 1 13/72

Проверка: 3 33/72 - 1 13/72 = 1 12/72 + 1 8/72

                   2 20/72 = 2 20/72

Ответ: х = 1 13/72.