Line joining points (p,a) and (p,-a)
Not sure what p70 means, p=70 maybe?
1. Slope
m = (-a - a) / (p - p)
That's a zero denominator, slope undefined.
Answer: line has no slope
2.
The equation is clearly
x = p
If p is really 70, that's
Answer: x = 70
3. Vertical lines have no y intercept. (Except when the line is the y axis in which case every point is a y intercept!)
Answer: y intercept does not exist
4. Slope of the perpendicular
This is a vertical line so the perpendicular is horizontal, zero slope
Answer: zero
