The value of a $20,000 car decreases every year, 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!

1 answer

Damon answered this for you yesterday, and pointed out your typo
http://www.jiskha.com/display.cgi?id=1335108312

I also agree that your equation should read

20000(1-.04)^t = 13000

then .96^t = .65
take log of both sides

log (.96^t) = log .65
use log rules ...

t(log .96) = log .65
t = log .65 / log .96 = 10.5527 = appr 10.6 years