## Intermediate Algebra (6th Edition)

$y=3$
A line perpendicular to $x=4$ has a slope of $0$. Using $y-y_1=m(x-x_1)$ or the Point-Slope Form, the equation of the line with slope $0$ and passing through $(-2,3)$ is \begin{array}{l} y-3=0(x-(-2)) \\\\ y-3=0 \\\\ y=3 .\end{array}