# 9.1 Systems of Equations in Two Variables

Solve a system of two linear equations in two variables by graphing.

Solve a system of two linear equations in two variables using the substitution method and the elimination method.

Use systems of two linear equations to solve applied problems.

A **system of equations** is composed of two or more equations considered simultaneously. For example,

is a **system of two linear equations in two variables**. The solution set of this system consists of all ordered pairs that make *both* equations true. The ordered pair $\left(2,-3\right)$ is a solution of the system of equations above. We can verify this by substituting 2 for `x` and $-3$ for `y` in *each* equation.

# Solving Systems ...

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