Exercise 7.1
https://drive.google.com/file/d/1gScMUTR92gHVZdNozgsVXfpD155_HD51/view?usp=drivesdk
Exercise 7.2
https://drive.google.com/file/d/1ggNGTyDor3t53AU-dk2BhHmWAAw8hlvF/view?usp=drivesdk
Exercise 7.3
https://drive.google.com/file/d/1gWnKFOX_tScAVNaCBDbTSdB4ZnyDYtd9/view?usp=drivesdk
