I. (Representative Consumer Utility Maximization with Quasi-linear Quadratic Utility (and Linear Demand System) Consider a representative consumer with the following quasi-linear utility function over three goods: U(q0, q1, q2) = q0 1q1 2q2 [q 2 1 2q1q2 q 2 2 ]/2, with i > 0, i > 0, and 2 < 1, where q0 is the numeraire good