Question 21422
The slope equation is: (change in y) / (change in x) = slope.

Think of the two points as  (x1, y1) and (x2, y2), so

x1 = 2
y1 = -8
x2 = 4
y2 = 1

change in y = y2 - y1
change in x = x2 - x1
{{{( 1 - (-8) ) / ( 4 - 2 ) = m }}}
{{{ 9 / 2 = m }}}