Answer: vertical --> x = 3 ; horizontal --> y = 15
Explanation:
A vertical line is one that goes straight up and down, without moving side-to-side. Thus, its x-coordinate is always the same, a constant.
So, vertical lines all have the form x = k, some constant.
In this case, x = 3 for the vertical line to go through point (3, 15).
A horizontal line is one that goes straight left and right, without moving up or down. Thus, its y-coordinate is always the same, a constant.
So, horizontal lines all have the form y = k, some constant.
In this case, y = 15 for the horizontal line to go through point (3, 15).
I hope this helps.