Hi!
The graph "x = 78" represents a vertical line passing through the point (78, 0).
Parallel lines always have the same slope, and for this equation a vertical line has an "undefined" slope.
Perpendicular lines have opposite inverse slopes. A line that's perpendicular to a vertical line is, of course, a horizontal line. Horizontal lines have a slope of 0.
Parallel to the equation: undefined
Perpendicular to the equation: 0
Hope this helps! Let me know if you need any other help! :0)
