As x changes from 1 to 2, 2 to 3, and 3 to 4, each change in x is 1. The corresponding changes in y from 19 to 15, from 15 to 11, and from 11 to 7, are each a change of -4 in y. For each change of 1 in x, the corresponding change in y is -4. From 4 to 33 in x, the change is 33 - 4 = 29. The corresponding change in y is 29 * (-4) = -116.
