\f0 Question 4 v Find the average value of the function x, 3;) = a: + y over the region R = [4, 8] x [1, 5]. 0 Question 2 v 8 0H pt Find ff 6 dA over the region R = {(m, y) | 0 g a: 5 6, 0 g y g 4} by identifying it as the volume of R a solid