85.12 Chapter two. First order and simple higher order ordinary differential equations. A Exercises at page 40

85.12.1 problem 1
85.12.2 problem 2
85.12.3 problem 3
85.12.4 problem 4
85.12.5 problem 5
85.12.6 problem 6
85.12.7 problem 7
85.12.8 problem 8
85.12.9 problem 9
85.12.10 problem 10
85.12.11 problem 11
85.12.12 problem 12