Answer
$x=-8$
This equation has no slope-intercept form equivalent.
Work Step by Step
A line with an undefined slope is a vertical line.
Vertical lines have equations of the form $x=k$, where $k$ is the x-coordinate of each point on the line.
The line passes through the $(-8, 1)$, whose x-coordinate is $-8$.
Thus, the equation of the line is $x=-8$. This equation has no slope-intercept form equivalent.