Every ordered pair listed is of the form (x,y). The first value is the x coordinate. The second value is the y coordinate.
The range is the set of y coordinates of the relation. In this case the y values are: 3, 4, 5, -2
Therefore the range is {3, 4, 5, -2}
Optionally you can sort the values from smallest to largest to get {-2, 3, 4, 5}