The book teaches the basics of solving equations and inequalities in easily understandable language. One of the main topics is the solving of quadratic equations, regardless of whether they already exist in normal form or have to be brought into it first. The author treats the p-q formula and the midnight formula as tools for this purpose. In addition, the book deals with linear equations and, in general, with the question of which manipulations one may make on an equation without changing its solutions. Furthermore, the most important inequalities are treated and strategies for their solution are shown. This Springer essential is a translation of the original German 1st edition essentials, Gleichungen und Ungleichungen by Guido Walz, published by Springer Fachmedien Wiesbaden GmbH, part of Springer Nature in 2018. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors.