PLEASE HELP A pizza parlor sells 320 pizzas per night when they charge $9.00 per pizza. The owner believes increasing the price by $0.15 will result in selling four fewer pizzas per night.
1. Write an expression that represents the cost of each pizza after x-number of $0.15 price increase.
2. Write an expression that represents the number of pizzas sold per night after x-number of $0.15 increase.