18.1 problem section 9.2, problem 1
 18.2 problem section 9.2, problem 2
 18.3 problem section 9.2, problem 3
 18.4 problem section 9.2, problem 4
 18.5 problem section 9.2, problem 5
 18.6 problem section 9.2, problem 6
 18.7 problem section 9.2, problem 7
 18.8 problem section 9.2, problem 8
 18.9 problem section 9.2, problem 9
 18.10 problem section 9.2, problem 10
 18.11 problem section 9.2, problem 11
 18.12 problem section 9.2, problem 12
 18.13 problem section 9.2, problem 13
 18.14 problem section 9.2, problem 14
 18.15 problem section 9.2, problem 15
 18.16 problem section 9.2, problem 16
 18.17 problem section 9.2, problem 17
 18.18 problem section 9.2, problem 18
 18.19 problem section 9.2, problem 19
 18.20 problem section 9.2, problem 20
 18.21 problem section 9.2, problem 21
 18.22 problem section 9.2, problem 22
 18.23 problem section 9.2, problem 23
 18.24 problem section 9.2, problem 24
 18.25 problem section 9.2, problem 25
 18.26 problem section 9.2, problem 26
 18.27 problem section 9.2, problem 27
 18.28 problem section 9.2, problem 43(a)
 18.29 problem section 9.2, problem 43(b)
 18.30 problem section 9.2, problem 43(c)
 18.31 problem section 9.2, problem 43(d)
 18.32 problem section 9.2, problem 43(e)
 18.33 problem section 9.2, problem 43(g)