у + 8 8/9 = 14 7/9 - 4 2/9; у = 14 7/9 - 4 2/9 - 8 8/9; у = 133/9 - 38/9 - 80/9; у = (133 - 38 - 80)/9; у = 15/9; у = 1 4/9. проверка: 14 7/9 - (1 4/9 + 8 8/9) = 4 2/9; 14 7/9 - (15/9 + 80/9) = 4 2/9; 14 7/9 - 95/9 = 4 2/9; (133 - 95)/9 = 4 2/9; 38/9 = 4 2/9; 4 2/9 = 4 2/9.