5 - х/2 + 3 - х/5 = 4
5 - 5х/10 + 3 - 2х/10 = 4
50 - 5х + 30 - 2х = 40
- 5х - 2х = 40 - 50 - 30
- 7х = - 40
х = - 40 : (- 7)
х = 5 5/7
Проверка: 5 - 40/7 * 1/2 + 3 - 40/7 * 1/5 = 4
5 - 40/14 + 3 - 40/35 = 4
5 - 200/70 + 3 - 80/70 = 4
5 + 3 - 280/70 = 4
8 - 4 = 4
4 = 4
Ответ: х = 5 5/7.