[MUSIC] Hello everyone and welcome to the first week in the mathematics for the Quantitative Foundations for International Business MOOC. This week, we will be discussing equations. As a preliminary study, it is important to learn some key mathematical concepts in order to deal with complex financial and business models. It is true that a financial model is a theoretical construct, a theoretical framework. However, we often use mathematics as a suitable tool to work and analyze those models. Therefore, if our model is mathematical it will be made up of some equations designed to describe the structure of the model. We use mathematical models, which often include one or more equations, whose solution determines the magnitudes of some variables we would like to understand better. For example, when analyzing economic data, such as, for example, inflation and interest rates. We may wish to understand how change interest rates will affect inflation. Then, we need to construct a model with describes the behavior of inflation when interest rates change such a model is made up of equations that relate inflation and other microeconomics variables to the interest rates. By relating a number of variables to one another in certain ways, such equations give mathematical form to the set of analytical assumptions we have chosen. Then, through the application of the relevant mathematical equations to these equations, we derive a set of conclusions. These conclusions, follow from the assumptions we made first. It may appear difficult, to begin with. To deal with expressions that involves several variables, with a large variety of names, denoted by different letters. In order to deal with economic business and financial studies, however, it is very important to be able to handle such algebraic expressions and equations with es. With this in mind, this first week provides some basic concepts in equations, with the aim of learning the basic terminology and the basic rules to solve equations that require more than one operation. To begin with, we study variables, constants, and parameters and then we introduce equations and identities. After these basic concepts, we'll learn how to solve equations. And then we started some application so far equations, to business formulas. The lecture is finishing by discussing ratios and proportions. The skills yo will acquire will form the basic understanding of how to deal with practical problems. Translate them into mathematical expressions and use standard business formulas to. Thank you very much. [MUSIC]