(19 3/29 - x) - 8 16/29 = 3 17/29
19 3/29 - x = 3 17/29 + 8 16/29
19 3/29 - x = 11 33/29 = 12 4/29
x = 19 3/29 - 12 4/29
x = 6 28/29
Спасибо большое! :)