Alice and Bob play the following extensive form game. There are two periods. Alice moves first in period 1 and chooses x1 [0, 10]. In period 2, Bob observes Alice's action and chooses x2 [0, 10]. The utility function of player i {Alice, Bob} is ui(x1, x2) = xi(9 x1 x2) xi if x1 + x2 9 and ui(x1, x2) = xi if x1 + x2 > 9. Find all subgame perfect equiliabria of this game. Show your work. [Note that you need to find strategies for each player, just listing actions on the equilibrium path is not enough.]