Economic models like the circular flow diagram are not physical models, but instead are diagrams or graphs or even mathematical equations that represent
y = 3x
If you divide the values of y by 3, you get the numbers in the x row every time. This shows that the equation to this data is y = 3x.
y = 3x
12 = 3 (4)
12 = 12 (true) This was an example to use as evidence that this equation is the one that matches this data.
For each hour the salary keeps increasing by $10.
Therefore for each increase in hour, salary is supposed to increase by 10.
however salary is not directly proportional to number of hours worked. If so then 5th hour worked should be $10 / hour x 5 hours = $ 50
Therefore it is visible that there's a fixed salary amount, with each increase in hour , salary keeps increasing.
If fixed amount is F, then for 5 hours worked,
$ 100 = F + $10 /hour x 5 hours
100 = F + 50
F = $ 50
then salary for 8 hours worked;
= 50 + 10x8
= 50 + 80 = $130
Therefore equation for the pattern is
s = 50 + 10h
h - number of hours