4. Shijun has the utility function: wory) = (x + 30)(y + 65). This utility function has nice negatively- sloped and convex indifference curves increasing northeasterly. Shijun faces fixed prices p, 3 0 and py > 0, and has a limited income m > 0. a. Find Shijun's Marshallian demand functions, I(Px,py, m) and y(p. py. Mi). Show your work. b. If the price of X is 814 and the price of Y is $16, how much X will Shijun buy when his income is $240