1. Suppose you wish to minimize the function f(x,y) = x^2-2xy+3y^2 subject to the constraint x+y =15. What is the value of x (not y!) in the solution? 2. Suppose we were given a firm's average (total) cost function. How could we derive its (total) cost function? A. Divide by quantity B. Mutiply by quantity C. Add fixed cost and variable cost together D. Differentiate average total cost with respect to quantity 3. Consider two events, A and B. Suppose P(A|B)=0.5 and P( A B) = 0.25. What is P(B)?