Use the same logs rules which were explained and demonstrated in
this other log question you posted yesterday.
The only difference here is that you're taking one log apart into three (one of which can be evaluated numerically), instead of putting three logs together into one. So it's the exact same rules and processes, just backwards.
If you get stuck, please reply showing your steps and reasoning so far, starting with "log_8(64x/y) = log_8(64x) - log_8(y)" and using
standard web-safe formatting, for clarity. Thank you!