72.23 Chapter 9. Laplace transforms. Section 50. Applications to differential equations. Problems at page 462

72.23.1 problem 3 (a)
72.23.2 problem 3 (b)
72.23.3 problem 3 (c)
72.23.4 problem 3 (d)
72.23.5 problem 3 (e)
72.23.6 problem 4