Section	Exercises
13.4	p.875: 3, 7, 13, 19, 22, 35, 41, 43, 53, 55, 57(a,c), 58(a,c), 60, 71, p.896: 43
13.6	p.895: 5, 7, 17, 18, 26, 34, 42
13.7	p.904: 3, 7, 9, 19, 28, 37, 40, 43, 45, 51