A system of equations is any set of simultaneous equations—two or more—that are intertwined and have to be determined together. They are usually a finite set of equations with the same unknowns, all of which have common solutions. A set of linear equations is said to be a linear system, while a set of homogeneous linear equations is called a homogeneous linear system. The number of equations is finite, meaning the solutions don’t go on forever like some with billions of answers. But a word of caution: Some problems use systems with hundreds of equations and just about the same number of variables.