3 Chapter 8, Ordinary differential equations. Section 3. Linear First-Order Equations. page 403

3.1 problem 1
3.2 problem 2
3.3 problem 3
3.4 problem 4
3.5 problem 5
3.6 problem 6
3.7 problem 7
3.8 problem 8
3.9 problem 9
3.10 problem 10
3.11 problem 11
3.12 problem 12
3.13 problem 13
3.14 problem 14