Problem 9 Recall that in problem 6 Tanner takes two classes: economics from Prof. Olimov and survival skills from Prof. Pear Grylls. Tanner wants to get the best possible grades in these two classes. a) Write utility function that represents Tanner's preferences over combinations of test scores (x1,x2) on midterm exams in Prof. Olimov's class: b) Write utility function that represents Tanner's preferences over combinations of test scores (x1,x2) on midterm exams in Prof. Pear Grylls' class