I have no idea on how to even approach this question, since i only know how to prove ones with the same base.
please help as soon as possible.
(1) The change of base formula:
(2) Cor. of (1): ....(by taking in part (1))
and are general terms here, not the and in your problem.
Apply the above formulas in the order they are given and you will have your proof. just to give you a direction (the manipulation can work in either) start with the left hand side of your equation
look at where you are starting and where you want to get. x and y are not the base of any log here, why did you make them the bases? you always want the bases to be a or b. now you want to start with an expression that has and and end up with an expression that has and