46. MULTI-STEP A flying disk has a radius of 4.9 inches. Jolanda discovers that adding a hole with a radius of 3.75 inches to the center of the disk reduces the weight of the disk, so it travels farther. Jolanda wants to experiment with the size of the disk to increase flying distance. In the new disks she creates, the sizes of the disks and holes are increased on decreased by the same amount. a. Write an expression for the area of the top of the new flying disks. b. Explain your solution process. ​