In mathematics, a system of linear equations (or linear system) is a collection of two or more linear equations involving the same variables.

In mathematics, a differential-algebraic system of equations is a system of equations that either contains differential equations and algebraic equations, or is equivalent to such a system.

In mathematics, a system of differential equations is a finite set of differential equations.

A system of polynomial equations (sometimes simply a polynomial system) is a set of simultaneous equations where the are polynomials in several variables, say , over some field .

In mathematics, a system of bilinear equations is a special sort of system of polynomial equations, where each equation equates a bilinear form with a constant (possibly zero).