12 * (1 3/4х + 5/8) = - 61/2
12 * 7/4х + 12 * 5/8 = - 61/2
84/4х + 60/8 = - 61/2
21х + 7,5 = - 30,5
21х = - 30,5 - 7,5
21х = - 38
х = - 38/21
х = - 1 17/21
Проверка: ( 7/4 * (-38/21) + 5/8) = - 38/12 + 5/8 = - 76/24 + 15/24 = - 61/24 * 12 = - 61/2
ответ: х = - 1 17/21.
