Answer:
Step-by-step explanation:
A line perpendicular to the y-axis, which is vertical, is a line that is horizontal. Perfectly horizontal lines always have a slope of 0. Thus, the equation of the line perpendicular to the one given and passing through the given point (5, 1) is
y - 1 = 0(x - 5) and
y - 1 = 0x - 0 and
y - 1 = 0 so
y = 1 is the equation you're looking for.
