64.8 Chapter 4, Section 4.1. Basic theory of linear differential equations. Exercises page 113

64.8.1 problem 1 (a)
64.8.2 problem 1 (b)
64.8.3 problem 2
64.8.4 problem 4 (a)
64.8.5 problem 8
64.8.6 problem 9
64.8.7 problem 10
64.8.8 problem 11
64.8.9 problem 12
64.8.10 problem 13