This has been driving me up the wall, I have a test the day after tomorrow and this is DEFINITELY going to be on the test. It seems simple, but for some reason I can't get the hang of it, please help.

***Rewrite the equation in terms of A and B

A=Log_{3}4 , B=log_{3}5

this equation--> log_{3}(15/2)

I've tried 3b+(a/2), but thats wrong. I know why it's wrong, but I dont know how to get the right answer.