Evaluate this expression for a=3 and b=4

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

How to do this , and can some one explain

The graph of y=x3 is transformed as shown in the graph below. which equation represents the transformed function?