Brealey, Principles of Corporate Finance, 13e, describes the theory and practice of corporate finance. We hardly need to explain why financial managers have to master the practical aspects of their job, but we should spell out why down-to-earth managers need to bother with theory. Throughout this book, we show how managers use financial theory to solve practical problems. Much of this book is concerned with understanding what financial managers do and why. But we also say what financial managers should do to increase company value.