# math - Additional Info

posted by
**Jane** on
.

The value of a $20,000 car decreases every, t. The equation below model this situation.

20,000(1-0.04t) = 13,000

How many years will the car be worth $13,000? Round to the nearest tenth if necessary.

I got 20,000(.96t)= 13,000, but I don't believe gives me the correct answer. Help!

typo - Damon, Saturday, April 21, 2012 at 8:26pm

this does not make sense:

" decreases every, t "

did it say it decreased 4% per year?

that would mean

.96^n =13/20

.96^n = .65

n log .96 = log .65

n = -.187/-.0177

= 10.6 years

math - Jane, Saturday, April 21, 2012 at 9:38pm

I understand most of the explanation except the part below:

n log .96 = log .65

n = -.187/-.0177

The answer is 10.6, but I don't know how to get passed .96t = .65. Please continue to help me. Thanks