Original Income = 15,000
New income = 20,000
The percentage Increase in the income can be calculated as:

%
The change in income = 20000 - 15000 = 5000
Using the values, we get:

%
=

%
This means, Pats income increased by 33.33% in a period of ten years
Plug in the given numbers (x) to the equation.
For example, let's take the first value it gives us.
-10(-2) +y=4
20+y=4
y=-16
Then you would put that on the table, and plug in the next value(s).
Hope this helped!
Yes 8/10 is equivalent to 4/5 or 16/20 ...