Answer:
Part a) The equation of the line in point slope form is
![y-264.70=39.95(x-6)](https://tex.z-dn.net/?f=y-264.70%3D39.95%28x-6%29)
Part b) The equation in slope intercept form is
Part c) The setup fee is $25
Step-by-step explanation:
Part a) write an equation in point slope form
Let
x ------> the number of months of service
y -----> the total cost
we know that
The equation of the line in point slope form is
![y-y1=m(x-x1)](https://tex.z-dn.net/?f=y-y1%3Dm%28x-x1%29)
where
m is the slope
(x1,y1) is a point that lie on the line
In this problem we have that the cost of $39.95 per month is equal to the rate or slope of the linear equation
![m=39.95\ \frac{\$}{month}](https://tex.z-dn.net/?f=m%3D39.95%5C%20%5Cfrac%7B%5C%24%7D%7Bmonth%7D)
we have that the point (6,264.70) is a solution of the linear equation
substitute the given values
----> equation in point slope form
Part b) write the equation in slope intercept form
The equation of the line on slope intercept form is
![y=mx+b](https://tex.z-dn.net/?f=y%3Dmx%2Bb)
where
m is the slope
b is the y-coordinate of the y-intercept
we have
![y-264.70=39.95(x-6)](https://tex.z-dn.net/?f=y-264.70%3D39.95%28x-6%29)
Isolate the variable y
Distribute right side
![y-264.70=39.95x-239.70](https://tex.z-dn.net/?f=y-264.70%3D39.95x-239.70)
Adds 264.70 both sides
![y=39.95x-239.70+264.70](https://tex.z-dn.net/?f=y%3D39.95x-239.70%2B264.70)
Part c) what is the setup fee?
The setup fee is the y-intercept of the linear equation
The y-intercept is the value of y when the value of x is equal to zero
In this problem, the y-intercept is the total cost when the number of months of service is equal to zero (the cost is equal to the setup fee)
For x=0
The setup fee is $25