Equation of a horizontal line

The equation of a horizontal line is

$y =$ The same number

Example

$y = 7$

No matter what value $x$ is, $y$ is 7.

$x = 2$ $y = 7$

$x = 1$ $y = 7$

$x = 0$ $y = 7$

$x = -1$ $y = 7$

$x = -2$ $y = 7$

The graph would be plotted as follows:

Plot a horizontal line on the graph which goes through the Y axis

And would look like this.

Now find the x axis value and y axis value y = 7

This is a horizontal line.