Jim’s utility function is uj (x, y) = xy. francis’s utility function is uf (x, y) = 2xy + 7. tammy’s utility function is ut (x, y) = √xy. oral’s utility function is uo(x, y) = x(y + 5). marjoe’s utility function is um(x, y) = (xy) 2 − 10. pat’s utility function is up (x, y) = 3x/y. billy’s utility function is ub(x, y) = −xy. (a) who has the same preferences as jim? (b) who has the same indifference curves as jim? (c) explain why the answers to (a) and (b) differ