The tutorial provides a detailed description of the main issues of the courses "Ordinary Differential Equations," "Operational Calculus," "Rows" and "Variation Calculus," which meets the requirements for minimizing the main mandatory program for the training of graduates. Methods of solving differential equations (DN) of the first and second orders and, in particular, Euler DN are considered. The theory is illustrated by auxiliary drawings and the solution of typical examples. Classical methods for solving first and second order remote controls are given.