I'm afraid that I don't understand the final goal: "simplest form." So I'll show you how I would do the problem and you can make your own decision if the answer is simple enough.

We're going to be using the change of base formula:

I'm going to choose my favorite base, e.

So

Skipping a couple of steps, you should arrive at

Which has the final form, as simply as I can write it:

The only other thing I can think of would be to subtract the fractions.

-Dan