um, CPhill is answering it and I'm sure his answer is more qualified.
But, you would basically put the normal log_2(5) on the numerator and log_2(3) on the denominator which is:
\(\frac{log_2(5)}{log_2(3)} \\OK\ so\ I\ used\ the\ change\ of\ base\ formula\ to\ do\ this... \\ \frac{log(5)}{log(3)} (simplify)\)
And you would enter that into your calculator.
(log(5))/(log(3))
But if you want to find out more about the change of base formula, I would suggest KhanAcdemy if you are not familiar with it...
link:
https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:logs/x2ec2f6f830c9fb89:change-of-base/a/logarithm-change-of-base-rule-intro
