# How do you write an equation of the horizontal line passing through the point (-7,4)?

Mar 14, 2018

$y = 4$

#### Explanation:

$\text{A horizontal line is parallel to the x-axis and passes }$
$\text{through all points in the plane with the same y-coordinate}$

$\text{the equation is } y = c$

$\text{where c is the value of the y-coordinate the line passes}$
$\text{through}$

$\text{the point here is } \left(- 7 , 4\right)$

$\Rightarrow y = 4 \text{ is the equation of the line}$
graph{(y-0.001x-4)((x+7)^2+(y+4)^2-0.04)=0 [-10, 10, -5, 5]}

Mar 14, 2018

$y = 4$

#### Explanation:

A horizontal line has a slope of $0$ and thus pases through all points of $x \in \mathbb{R}$ Which includes $x = - 7$

The equation of a straight line with slope $\left(m\right)$ and $y -$intercept $\left(c\right)$ is:

$y = m x + c$

In this case $m = 0 \mathmr{and} c = 4$

Hence, $y = 4$ is the equation of our straight line. as shown in the graphic below.

graph{(y-0.000x-4)((x+7)^2+(y-4)^2-0.1)=0 [-14.24, 14.24, -7.12, 7.12]}