The second logarithm property needed is:
(which is realy just the previous property in disguise),
Therefore we have:
But the number who's log (to any base) is 1 is the base itself, and since we have logs to the base here;
You are almost correct Jonathan (hey that's my name too!).
So we have:
Which goes to:
Now raise both to a base of 10:
You can solve the quadratic, make sure to check that both solutions work.