Well if the two numbers are equal to 5x(8+3).
Lets say that these two numbers are X and Y,
So that would be X + Y = 5(8+3)
which means X + Y = 55
You could write that as a fuctions Y = 55 - X
Now by using the graph you get and the X values of [0,55] ( This means every value from 0 to 55 ), you will get a X and Y value that if you added up together will give you the value of 8(5+33)
An examples for the answers would be
(0,55) (1,54) (2,53) (3,52) (4,51) (5,50) (6,49) ... it goes on until x reaches 55.