x / (1/3- 5/6) = 8/9
x / (2/6 - 5/6) = 8/9
x / (-3/6) = 8/9
x / (-1/2) = 8/9
x * (-2) = 8/9
x = 8/9 / (-2)
x = - 4/9
Проверка:
-4/9 / (1/3-5/6)
-4/9 / ((2-5)/6)
-4/9 / (-3/6)
-4/9 * -6/3
-4/9 * -2 = 8/9
А твой ответ: 1 7/15 = 22/15
22/15 / (-3/6)
22/15 * -6/3
22/15 * -2 = -44/15 (что не равно 8/9)