Lena does a weekly exercise program consisting of cardiovascular work and weight training. Each week, she exercises for at least 9 hours. She spends at most 11 hours on weight training. She spends at most 4 hours doing cardiovascular work. Let x
denote the time (in hours) that Lena spends doing cardiovascular work. Let y denote the time in hours) that she spends on
weight training. Shade the region corresponding to all values of x and y that satisfy these requirements.