Sammy bought a new car. The depreciation equation is given by f (x) = 30,000 (.85) x, where x represents the number of years since the purchase of the car, and f (x) represents the value of the car. By what percent does Sammy's car depreciate each year?

In a depreciation equation, you multiply the value of the car by the percent of depreciation minus 1.

In the given equation you are multiplying the value of the car by (.85)

This means the percent of depreciation would be 1 - 0.85 = 0.15 which is 15%

The car depreciates by 15% every year.

Its B