The given data is
x f(x)
---- --------
12 0
20 800
30 1800
where
x = number of clients per month
f(x) = monthly revenue
A graph of the data is shown below.
Let the equation of the line be
y = mx + c
The x-intercept is 12, therefore
12m + c = 0 (1)
The line passes through (30, 1800) and (12,0). Therefore the slope is
m = 1800/(30-12) = 100 (2)
From (1), obtain
c = -12m = -12*100 = -1200
Therefore
y = 100x - 1200
Answer: D. f(x) = 100x - 1200
Provide info about the question
This boils down to simple algebraic manipulation.

So one possible ODE (the simplest, in fact) is

Answer:
James needs to earn 78 more dollars.
Step-by-step explanation:
If you add up all of the money James has earned, (1 + 7 + 14), it equals 22. If you subtract 22 from 100, it equals 78. Therefore James needs to earn 78 more dollars.