7 Chapter 2, Section 2.4. Special integrating factors and transformations. Exercises page 67

7.1 problem 1
7.2 problem 2
7.3 problem 3
7.4 problem 4
7.5 problem 5
7.6 problem 6
7.7 problem 7
7.8 problem 8
7.9 problem 9
7.10 problem 10
7.11 problem 11
7.12 problem 12
7.13 problem 13
7.14 problem 14