Question

log7 25 / log7 5 - log5 8 / log5 2

Answer 1

Logarithms.
$\frac{Log_7 25}{Log_7 5} - \frac {log_5 8}{log_5 2}\\\\= \frac{Log_7 5^2}{Log_7 5} - \frac {log_5 2^3}{log_5 2}\\\\= 2*\frac{Log_7 5}{Log_7 5} - 3*\frac {log_5 2}{log_5 2}\\\\= 2 - 3 = -1$