The function which models Damian's pay is : f(x) = 10x + 8
From the table, we can deduce the linear function in the form :
b = change in y / change in x
change in y = (38 - 18) = 20
change in x = (3 - 1 ) = 2
b = 20/2
b = 10
Using the point (1, 18) to find 'c' :
y = 10x + c
18 = 10(1) + c
18 - 10 = c
c = 8
Now we have :
y = 10x + 8
Hence, Damian's pay is represented by : 10x + 8