$x=-4$ Refer to the graph below.
Work Step by Step
RECALL: A vertical line has an equation of the form $x-h$. Every point on the line has an x-coordinate of $h$. The given line is vertical and passes through the point $(-4, 3)$. This point has an x-coordinate of $-4$. Since every point on a vertical line has the same x-coordinate, then the is equation of the given line is $x=-4$. Refer to the graph in the answer part above.