Answer:
a)
b) ![profit=\$8](https://tex.z-dn.net/?f=profit%3D%5C%248)
c) They'd have lost $1000 if they had sold no calendars.
Step-by-step explanation:
a) The equation of the line in Slope-Intercept form is:
![y=mx+b](https://tex.z-dn.net/?f=y%3Dmx%2Bb)
Where "m" is the slope and "b" is the y-intercept.
In this case we know that "y" represents the profit of loss and "x" the number of calendars sold.
Then, according to the exercise, the line passes through these two points:
and ![(200,600)](https://tex.z-dn.net/?f=%28200%2C600%29)
Then, we can find the slope of the line with the formula ![m=\frac{y_2-y_1}{x_2-x_1}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7By_2-y_1%7D%7Bx_2-x_1%7D)
![m=\frac{-360-600}{80-200}=8](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B-360-600%7D%7B80-200%7D%3D8)
Now, we can substitute the slope and one of those points into
and solve for "b":
![600=8(200)+b\\\\b=-1000](https://tex.z-dn.net/?f=600%3D8%28200%29%2Bb%5C%5C%5C%5Cb%3D-1000)
Then, subtituting values, we get that the equation that describes the relation between the profit of loss and the number of calendars sold, is:
b) The slope of the line is the profit they made from selling each calendar
![profit=8](https://tex.z-dn.net/?f=profit%3D8)
c) The y-intercept is the amount they would have lost if they had sold no calendars:
![b=-1000](https://tex.z-dn.net/?f=b%3D-1000)
They'd have lost $1000 if they had sold no calendars.