SOLUTION: A car purchased in 1998 is currently valued at $12000. If it has decreased in value exponentially at a rate of 4% per year, determine the original cost of the vechicle. I do know

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A car purchased in 1998 is currently valued at $12000. If it has decreased in value exponentially at a rate of 4% per year, determine the original cost of the vechicle. I do know       Log On


   

Question 128065: A car purchased in 1998 is currently valued at $12000. If it has decreased in value exponentially at a rate of 4% per year, determine the original cost of the vechicle.
I do know that the formula I should use is A=Ao(1-r)^t or some variation of it but I do not know how to fill it in ???????
Answer by mr.barrett(5) About Me  (Show Source):
You can put this solution on YOUR website!
A%5B0%5D= original cost
A = current value = 12000
t = time in years = 2008 - 1998 = 10
r = rate of decrease = .04


Substituting these values into A=A%5B0%5D%281-r%29%5Et we have 12000=A%5B0%5D%281-.04%29%5E10.

12000=A%5B0%5D%28.96%29%5E10

12000=A%5B0%5D%28.664832636%29

12000%2F.664832636=%28A%5B0%5D%28.664832636%29%29%2F.664832636

18049.66=A%5B0%5D