the equation to find any slope given two points is (y1-y2)/(x1-x2)
given this equation, the slope of problem 24 would be (6-3)/(-1-4) or (3-6)/(4+1) which is equal to -3/5,
depending on which point you call (x1,y1) and (x2,y2)
calling either of the points 1 or 2 will still result in the same slope