You may want to review logarithms first.

One rule that logarithms follow is that the logarithm of a
product is the *sum* (*not* product!) of the
logarithms of the two factors. Thus, you can rewrite
log_{8} (6 * 5) as log_{8} 6 + log_{8} 5.
Note that both of the new logarithms should have the same base as
the given logarithm.