Economists use the term equilibrium to describe the balance between supply and demand in the marketplace. Under ideal market conditions, price tends to settle within a stable range when output satisfies customer demand for that good or service. Equilibrium is vulnerable to both internal and external influences. The appearance of a new product that disrupts the marketplace, such as the iPhone, is one example of an internal influence. The collapse of the real estate market as part of the Great Recession is an example of an external influence.

Often, economists must churn through massive amounts of data to solve equilibrium equations. This step-by-step guide will walk you through the basics of solving such problems.