A vertical line has the same x-coordinate for all points on the line. Since the line passes through the point (5, 1), the x-coordinate is 5. Therefore, the equation of the vertical line is simply:
x = 5
This means that for every point on this line, the x-value will always be 5 while the y-value can be any real number. So, the line runs straight up and down at x = 5 on the coordinate plane.