Find the slope, if it exists, of the line containing the pair of points.

(-6.8,11.8) and (-6.4,7.6)

The slope between two points P1(x1,y1) and P2(x2,y2) is given by

m=(y2-y1)/(x2-x1) if (x2-x1)≠0
If (x2-x1)=0, the slope does not exist (infinite).