78.4 Chapter 5, Laplace transforms. Problems section 5.7

78.4.1 problem 3.a
78.4.2 problem 3.b
78.4.3 problem 3.c
78.4.4 problem 3.d
78.4.5 problem 3.e
78.4.6 problem 4.a
78.4.7 problem 4.b
78.4.8 problem 4.c
78.4.9 problem 12.a
78.4.10 problem 12.b
78.4.11 problem 12.c