Answer:
so whats the question?
Step-by-step explanation:
Answer:
y = 14
Step-by-step explanation:
y ∝ 
=> y =
-------------(1)
<em><u>Where k is the constant of proportionality</u></em>
Now,
x = 7, y = 4
<em>Putting in (1)</em>
4 = 
So,
=> k = 28
Now y = ? when x = 2
<em>Putting x and k in (i)</em>
y = 
y = 14
It is y = 12x + 20.
You start with 20 as the y-intercept because that is the starting amount that you paid. The constant rate of change is 12 dollars per book. So, 12 time however many books written as 12x. Hope that helps! :)