-x = -1. Anything “X” equals to the number One. So do Y = -1 + 1.
You can see that every decade the income increases by 6,250. So if you want to do 5 years instead you would have to add 3,125 to the income of 1980 to find what the income was for 1985. Now you add 33,750+3,125= 36,875. The financial aid cutoff for 1985 would be $36,875.
