Profit is the difference between revenue and cost. The revenue, in dollars, of a company that manufactures cell phones can be modeled by the polynomial 2x2 + 55x + 10. The cost, in dollars, of producing the cell phones can be modeled by 2x2 – 15x – 40. The variable x represents the number of cell phones sold. What expression represents the profit, and what is the profit if 240 cell phones are sold?

40x – 30; $2,400
40x – 30; $9,570
70x + 50; $16, 850
70x + 50; $28,800