If this is indeed your question, I don't think logarithms will help you much. There's no way in isolating x from log(x - 1.5) so you can't do all that much after what you've done.
If you were to attempt to solve it:
(Raised both sides to the power of 20)
(via binomial theorem)
You would somehow have to find the roots of that quintic equation, keeping in mind that
There seems to be one real root: