Properties of Logarithms
There are several important facts to remember about logarithms. First you want to remember what the notation means.

log _a b = x just means that a^x = b.

Next, you want to remember that the natural log is just log base e.

Finally, there are some properties to keep in mind:

log_ca + log_cb = log_c(ab)
log_ca - log_cb = log_c(a/b)
log_ca^x = x log_ca
log_cc = 1
c ^log_ca = a
log_ca = [log_ba]/[log_bc] for any number b that you like.

If you remember these properties of logs, you should be able to do almost any log problem.