2. (7 pts) In a class of 120 students, everybody would take two hamburgers if the price were zero, and no one would buy hamburgers if the price were $4 or more. Assume that the class demand curve for hamburgers is linear and give a formula (a) (3 pts) describing quantity as a function of price (demand curve) (b) (3 pts) describing price as a function of quantity (this is sometimes called the inverse demand curve) (1 pt) Explain what the equation tells you for the demand for hamburgers when the price is $3.99