4. Willi Spends all his monetary income m 0n sausages (x1) and beer (x2). The prices are normalized in such a way that the unit price of sausages is \"p " and the unit price of beer is l. Willi's utility function is U(xl:x2) : X1X2+1OXL a. Set up Willi's utility maximization problem and derive his demand for sausages and beer (Willi 's preferences are Standard, you are allowed not to veri; it). b. Draw Willi's incomeconsumption curve. c. Suppose at the current prices and income Willi buys positive quantities of both goods. As Willi's income increases, what will happen to the share of income he spends on sausages? Share of income he spends on beer? Back up your answer with calculations