What is the slope of the line?

Can someone explain the elimination method to me for this problem?

Complete the table for different values of x in the polynomial expression -7x2 + 32x + 240. then, determine the optimal price that the taco truck should sell its tacos for. assume whole dollar amounts for the tacos.

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?