8) log1(9-4x) - log1= = log115; 2 1 2 3 2

8) log_1/2(9 - 4x) - log_1/2(1/3) = log_1/215

Используем свойство логарифмов: log_a b - log_a c = log_a (b/c)

log_1/2((9 - 4x)/(1/3)) = log_1/215

(9 - 4x) * 3 = 15

27 - 12x = 15

-12x = -12

x = 1

Проверка:

log_1/2(9 - 4*1) - log_1/2(1/3) = log_1/215

log_1/2(5) - log_1/2(1/3) = log_1/215

log_1/2(5 / (1/3)) = log_1/215

log_1/2(5 * 3) = log_1/215

log_1/215 = log_1/215

Ответ: x = 1