10. logo,46-log62,5

10. $$\log_{0.4} 6 \cdot \log_6 2.5 = \frac{\log_6 6}{\log_6 0.4} \cdot \log_6 2.5 = \frac{1}{\log_6 \frac{2}{5}} \cdot \log_6 \frac{5}{2} = \frac{\log_6 \frac{5}{2}}{\log_6 \frac{2}{5}} = -1$$

Ответ: -1