2 15/2 х-3* (5+11/18 х) = 19
2 15/2 х - 15-33/18 х = 19
19/2 х -33/18 х = 19+15
171/18 х-33/18 х = 34
138/18 х = 34
х = 34:138/18
х = 34*18/138
х = 102/23 = 4 10/23
Проверяем:
19/2*102/23 - 3*(5+11/18*102/23) = 969/23 - 3*(5+561/207)= 969/23-3*1596/207 =
= 969,23-4788/207 = 42,13-23,13 = 19
Ответ: 4 10/23.