84.10 Chapter 5. Homogeneous differential equations. Supplementary problems

84.10.1 problem 5.11
84.10.2 problem 5.12
84.10.3 problem 5.13
84.10.4 problem 5.14
84.10.5 problem 5.15
84.10.6 problem 5.16
84.10.7 problem 5.17
84.10.8 problem 5.18
84.10.9 problem 5.19