Help with finding values of $4^{ax}=b \times 8^x$

Question

The question is:

Given that there is more than one value of $x$ to the question $4^{ax} = b \times 8^x$, find all possible values of $a$ and $b$.

I know that you can use logs to solve this question, but are there any other methods? (like deductions or something like that?)

Thanks!