When a pizza place sold its large pepperoni pizza for $15.00, it sold 420 pizzas per week. When they put the price up by $0.15, the weekly sales dropped by 6 pizzas per week. Assuming a linear relationship between price and sales:

Find a formula for weekly sales as a function of the pizza price .

Find a formula for the weekly revenue from sale of this item as a function of the price .

Use any method to determine the price p that will maximize the revenue , and give also the maximum weekly revenue.