Решите уравнение х + 2/3 = 1/3 - 3/25 х

2/5х + 2/3 = 1/3 - 3/25х
2/5х + 3/25х = 1/3 - 2/3
10/25х + 3/25х = - 1/3
13/25х = - 1/3
х = - 1/3 : 13/25
х = - 1/3 * 25/13
х = - 25/39

Проверка: 2/5 * (- 25/39) + 2/3 = 1/3 - 3/25 * (- 25/39)
                  - 10/39 + 26/39 = 13/39 + 3/39
                   16/39 = 16/39