I'm a freshman at UPenn, and taking an intro to econ class. While doing some online homework, this question popped up, and I thought you guys might get a kick out of it: In the small town of Negreanu, there is a competitive market for decks of playing cards.Suppose that the demand curve is a straight line and is given by the following equation:P = 9 - (2/3)QD, where P is the price per deck and QD is the quantity demanded per day.The supply curve is also a straight line and is given by the following equation:P = 2 + (1/2)QS, where P is the price per gallon and QS is the quantity supplied per