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
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