Вычислим log43 + log425 + log4(16/75).
Используем свойство логарифмов: logax + logay = loga(x * y)
log43 + log425 + log4(16/75) = log4(3 * 25 * (16/75)) = log4(3 * 25 * 16 / 75) = log4(1200/75) = log416 = x
4x = 16
4x = 42
x = 2
Ответ: 2