The rate of change is the ratio of the change in Y to the change in X.
When Y changes from -40 to 4, that is an increase of 44 (4--40=4+40=44), so the change in Y is +44. The corresponding change in X is from -3 to 1, so the change in X is +4 (1--3=1+3=4). The ratio of the change in Y to the change in X is 44/4=11.
Try doing the same computation going from the second row to the third row and you will get the same ratio of 11.
