Work Step by Step
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 a slope of zero is horizontal, the equation of which is of the form $y=k$ where $k$ is the y-intercept. All points on the line have a y-coordinate of $k$. The given line has a slope of zero therefore it is horizontal and its equation is of the form $y=k$. The line contains the point $(-3, 12)$. The y-coordinate of this point is $12$. Thus, the line's equation is $y=12$. The equation of the line cannot be written in slope-intercept form.