Precalculus (6th Edition)

$x=5$
RECALL: (1) The slope-intercept form of a line's equation is $y=mx+b$ where $m$=slope and $(0, b)$ is the line's y-intercept. (2) A line with an undefined slope is vertical, the equation of which is of the form $x=h$ where $h$=x-intercept. All points on the line have an x-coordinate of $h$. The given line has an undefined slope therefore its equation is of the form $x=h$. The line contains the point $(5, 1)$. The x-coordinate of this point is $5$. Thus, the line's equation is $x=5$. The equation of the line cannot be written in slope-intercept form.