PLEASE answer this correctly bc i will give u brainliest and extra points

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?  

We just started the introduction into circles and i have no idea how to do this.

Which graph represents the equation y =4x