(-1,4) and (5,8) is (x1,y1) and (x2,y2). The slope is m=(y2-y1)/(x2-1). Substitute and evaluate to find the slope.
Algebra - Reiny, Monday, September 19, 2011 at 5:04pm
Just do what it says ....
m = (8-4)/(5 - (-1))
finish it up.
btw, your formula conains a typo, should say
m = (y2-y1)/(x2-x1)