Okay first, breathe! It's gonna be okay
So this is simply a linear function/equation/system.
How you do this is by plugging in the numbers provided in the left column of the table (2, 4, 6, 8) into the equation provided, (f=19s+9).
For example, for the top one, 2, what they did was substitute 2 for s which looks like this --> 19(2) and the whole equation --> f= 19(2) +9
sooo.. if you were to solve you would get 47 (PEMDAS)
You can then do this for the remaining ss.
But if you're just looking for the answers then they are:
4: 85
6: 123
Hope you do good :)
