If m = 8, how many solutions are there for the expression m - 8? what is it going to be? 0 ? 1 ? 2 ? or infinite ?

Solutions for the expression:
(m - 8)

if m = 8, 
Solution for the expression m - 8 = 8 - 8 = 0.

So there is only 1 solution for the expression.

(6,0) i hope it makes enough sense

so the perpendicular line goes through the given pointyou would get a perpendicular line at some random location

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.