65.19 Chapter 10. Applications of Systems of Equations. Exercises 10.2 page 432

65.19.1 problem 1
65.19.2 problem 2
65.19.3 problem 3
65.19.4 problem 4
65.19.5 problem 5
65.19.6 problem 6
65.19.7 problem 7
65.19.8 problem 8