Plz plz plz help i don't know what to do it's due at midnight

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?  

X2 + y 2 = 36 x + y = 6 solve the system of equations.

Which of the following quartic functions has x = –1 and x = –2 as its only two real zeroes?