The sum of seven and the quotient of a number x and 8

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?  

The function models the number of accidents

Find the zeros of each function. f(x) = 6x^2 - 7x - 20