## Key Concepts

**Graph a linear equation by plotting points.**- Find three points whose coordinates are solutions to the equation. Organize them in a table.
- Plot the points on a rectangular coordinate system. Check that the points line up. If they do not, carefully check your work.
- Draw the line through the points. Extend the line to fill the grid and put arrows on both ends of the line.

**Graph of a Linear Equation:**The graph of a linear equation \(ax+by=c\) is a straight line.- Every point on the line is a solution of the equation.
- Every solution of this equation is a point on this line.

## Glossary

### horizontal line

A horizontal line is the graph of an equation that can be written in the form \(y = b.\) The line passes through the *y-*axis at \(\left(0, b\right)\)

### vertical line

A vertical line is the graph of an equation that can be written in the form \(x = a.\) The line passes through the *x-*axis at \(\left(a, 0\right)\).