Answer: m = - 2200
Step-by-step explanation: Slope of a line is a number which describes the steepness and direction of a linear graph. It is represented by the letter m.
The year a car is bought and its price means:
f(0) = 31,500
Five years later, the price is $20,500, i.e.:
f(5) = 20,500
With these two pairs of value, slope is calculated as:
[tex]m = \frac{y-y_{0}}{x-x_{0}}[/tex]
[tex]m = \frac{20500-31500}{5-0}[/tex]
[tex]m = \frac{- 1100}{5}[/tex]
m = - 2200
The slope of the depreciation line is m = -2200 and it is negative because the line decreases along time.