For these kind of problems you want to put the numbers raised to an exponential power to be the same, i.e. if 2^x=8^5, then I want to change 8 to 2^3. This would make the equation 2^x=(2^3)^5. Under the rules for exponents, the left hand side becomes 2^15 (3x5), making the equation 2^x=2^15, so x=15 for the left hand side to equal the right hand side.
For your problem, what is the common base between 3 and 9?
Then once you have a common base, you can eliminate the base, and you will have a quadratic equation, which can be set equal to zero and use the zero product property to solve.
I hope this helps. John