This lecture covers the methods for solving differential equations, focusing on the method of undetermined coefficients and the variation of constants. The instructor begins by reviewing previous examples of linear equations and their solutions. The general solution of the associated homogeneous equation is derived, followed by the search for a particular solution of the complete equation. The lecture emphasizes the importance of determining the correct form of the solution and the coefficients involved. The instructor explains the process of integrating and finding solutions, including the use of specific integrals and the significance of choosing the right functions. The method of undetermined coefficients is highlighted as a more efficient approach compared to the variation of constants, especially when dealing with constant coefficients. The lecture concludes with examples demonstrating the application of these methods to various types of differential equations, reinforcing the concepts discussed throughout the session.