9. Each week, you have a total of 80 hours to split between a hours of work and y hours of leisure. The value to you of a hours of work is given by the function 260x - x2. The value to you of y hours of leisure is 220y - y". You want to arrange your work and leisure times to yield the maximize the total value to you. What values of x and y maximize the value to you? (Give your answer as an ordered pair (x, y).)