15. Rahj owns a hardware store. For every increase of 10¢ in the price A of a package of batteries, he estimates that sales decrease by 10 packages per day. The store normally sells 700 packages of batteries per day, at $5.00 per package. a) Determine an equation for the revenue, y, when x packages of batteries are sold. b) What is the maximum daily revenue that Rahj can expect from battery sales? How many packages of batteries are sold when the revenue is at a maximum? also,how to get the zeros and the equation​