This volume proves that in recent years, linear mathematical models have assumed an important role in almost all the physical and social sciences, and, as it was expected, this development has stimulated a remarkable growth of interest in linear algebra. Ordinary Differential Equation has been furnished in the book with a number of abbreviations for convenience and to get rid of the boredom of repetition of the same chain of words. In Laplace Transformation, a few identities of operations have been introduced as well.