Question

130 ЗАДАНИЕ ЛОГАРИФМ​

Answer 1

log (ab) a = 5

(ab)^5 = a

a^5*b^5 = a

b^5 = a^-4

b = a^(-4/5)

по одз a, b > 0 все нормально

log (√ab) ⁵√a / ⁸√b = log(√a*a^(-4/5)) a^1/5 / a^((-4/5)*(1/8)) = log (a^1/10) a^1/5 / a^(-1/10) = log(a^1/10) a^(3/10) = 10*3/10 log(a) a = 3

ответ D

или log(a) b = 1/log(b) a

log(a) x/y = log(a) |x| - log(a) y