Posted by **sophia** on Saturday, November 7, 2009 at 11:00pm.

The value of a car decreases at a constant rate as it grows older. When the car is 2 years old, it is worth $23,000. When the car is 5 years old it is worth $15,500.

Write and equation relating y (value of the car $) to x (age of car).

Is it y-23,000=-2500(2)-5 ??

- math -
**Reiny**, Saturday, November 7, 2009 at 11:12pm
so you are looking for a linear relation in the form y = mx + b

where you are given two points

(2,23000) and (5,15500)

so slope = (15500-23000)/(5-2)= 7500/3

= -2500

so y = -2500x + b

sub in the first point

23000 = -2500(2) + b

b = 28000

finally :

y = -2500x + 28000

- math -
**sophia**, Saturday, October 22, 2016 at 1:09pm
how did you get b= 28000

## Answer This Question

## Related Questions

- math - The value of a car decreases at a constant rate as it grows older. When ...
- Math - The equation V = -2000t + 20,000 describes the value in dollars of a ...
- EASY Math - The equation V = -2000t + 20,000 describes the value in dollars of a...
- maths - a car depreciates at rate of 10%per year. the car cost £20000 new. (a) ...
- MATH - a rule of thumb used by car dealers is that the trade in value of a car ...
- MATH - NEED EXTREME HELP!@#$%^a rule of thumb used by car dealers is that the ...
- Math - The depreciation rate, r, for a $50,000 news car is given by the function...
- Algebra 2.. - a rule of thumb used by car dealers is that the trade in value of ...
- Algebra 1 - The value of a certain new car (time = 0 years old) is $14,000. ...
- College Algebra - A cars value is declining exponentially. The car is currently...

More Related Questions