Mathematics » Introducing Graphs » Graphing Linear Equations

# Key Concepts

## Key Concepts

• Graph a linear equation by plotting points.
1. Find three points whose coordinates are solutions to the equation. Organize them in a table.
2. Plot the points on a rectangular coordinate system. Check that the points line up. If they do not, carefully check your work.
3. 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 $$\left(a, 0\right)$$.