88.17 Chapter 5. Special Techniques for Linear Equations. Exercises at page 127

88.17.1 problem 5
88.17.2 problem 6
88.17.3 problem 7
88.17.4 problem 8
88.17.5 problem 9
88.17.6 problem 10
88.17.7 problem 11
88.17.8 problem 12