The logs rules work "backwards", so you can condense ("compress"?) strings of log expressions into one log with a complicated argument. When they tell you to "simplify" a log expression, this usually means they will have given you lots of log terms, each containing a simple argument, and they want you to combine everything into one log with a complicated argument. "Simplifying" in this context usually means the opposite of "expanding".
There is no standard definition, in this context, for "simplifying". You have to use your own good sense. If they give you a big complicated thing and ask you to "simplify", then they almost certainly mean "expand". If they give you a string of log terms and ask you to "simplify", then they almost certainly mean "condense".
