83.11 Chapter VI. Linear equations with constant coefficients. Ex. XIII at page 106

83.11.1 problem 1
83.11.2 problem 2
83.11.3 problem 3
83.11.4 problem 4
83.11.5 problem 5
83.11.6 problem 6
83.11.7 problem 7
83.11.8 problem 8
83.11.9 problem 9
83.11.10 problem 10
83.11.11 problem 11
83.11.12 problem 12