11. logo.85. logs 1, 25

log_0.85 ⋅ log₅1,25 = log_0.85 ⋅ log₅5/4 = log_0.85 ⋅ (log₅5 - log₅4) = log_0.85 ⋅ (1 - log₅2²) = log_0.85 ⋅ (1 - 2log₅2)

Ответ: log_0.85 ⋅ (1 - 2log₅2)