88.5 Chapter 2. Differential equations of first order. Exercise at page 35

88.5.1 problem 1
88.5.2 problem 2
88.5.3 problem 3
88.5.4 problem 4
88.5.5 problem 5
88.5.6 problem 6
88.5.7 problem 7
88.5.8 problem 8