(5 1/3)х - 1 = 1 2/9
(16/3)х = 1 2/9 + 1
(16/3)х = 2 2/9
(16/3)х = 20/9
х = 20/9 : 16/3
х = 20/9 · 3/16
х = (5·1)/(3·4)
х = 5/12
Проверка: 5 1/3 · 5/12 - 1 = 1 2/9
16/3 · 5/12 - 1 = 1 2/9
80/36 - 1 = 1 2/9
20/9 - 9/9 = 1 2/9
11/9 = 1 2/9 - верно
