The value of your car one year after you purchased was $12,500. four years after you purchased it, the cars value was $8,100?

 The value of your car one year after you purchased it was $12,500. 

 Four years after you purchased it, the car's value was $8,100.

 a) 

 Write two ordered pairs of the form 

 (number of years after purchase, value of the car).

 Car value one year after purchase was $12,500

 Its value four years after purchase was $8,100

 b). 

 Algebraically calculate the slope of the line between these two points. 

 c). 

 Interpret the slope as a rate of change.

First represent each value as an ordered pair (aka a "point").

Year 1 = 12500 --> (1, 12500)

Year 4 = 8100 --> (4, 8100)

If you have two points, the slope is calculated as change in y divided by change in x.

m = (y2 - y1) / (x2 - x1)

m = (8100 - 12500) / (4 - 1)

m = -4400 / 3

m = -1466.66666...

It means that the value of the car goes down by about $1466.67 per year.