Which of the following is a correct next step to solve the equation

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?  

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

Which table shows a proportional relationship between miles traveled and gas used?