What is the slope of the line segment XY?
2
1/2
-1/2
-2

the line has points (-1,3) and (1,-1)
slope = change in y over change in x
change in y = 3- -1 = 3+1 =4
change in x = -1 - 1 = -2
slope = 4/-2 = - 4/2 = -2