28.2 Chapter 2, Equations of the first order and degree. page 20

28.2.1 problem 1
28.2.2 problem 2
28.2.3 problem 3
28.2.4 problem 4
28.2.5 problem 5
28.2.6 problem 6
28.2.7 problem 7
28.2.8 problem 8
28.2.9 problem 9