Introductory concepts, initial value problems. First- and second-order ordinary differential equations, separable, homogeneous, Bernoulli, Ricati, Euler, variation of parameters, exact equations and integrating factors. Applications in problems from mechanics. Linear independence and the Wronskian. Linear differential equations with constant coefficients. Laplace transform. Homogeneous and non-homogeneous equations with constant coefficients. Linear differential equations with variable coefficients. Power series solution method.