The slope of the line is: m= (Ysub2 - Ysub1) / (Xsub2 - Xsub1), where m is the slope of the line and Xsub1 is not equal to Xsub2.
Solution: Let the first ordered pair (4, 8) be called (Xsub1, Ysub1) and the second ordered pair (1, 6) be called (Xsub2, Ysub2).
Substituting the values for m = (Ysub2 -Ysub1) / (Xsub2 - Xsub1) we have
m = (6-8) / (1-4)
m = -2 / -3
m = 2/3 Therefore the slope of the line is 2/3.