You may want to review simplifying logarithms first.

These rules can also be applied the other way, to change an expression with lots of simple logarithms into one more complicated one. For example, log4 1 − 1 ⁄ 9 * log4 a = log4 (1 / a1 ⁄ 9).

Note that this only works if the bases of the logarithms are the same.