A new car costs 13,000 and is depreciating by $900 each year. how much will the car be worth after 4 years

If the car is depreciating by $900 each year, after four years it will depreciate by 4 * $900 = $3 600.

Now we just have to do the substracting:

$13 000 - $3 600 = $9 400

Answer: After four years the car will be worth $9 400.