Question

The resale value of a textbook decreases by 25% with each previous owner. A new textbook is sold for $85. Which function represents the resale value of the textbook after x owners?

f(x) = 85(1 – 0.25)x
f(x) = 85(1 + 0.25)x
f(x) = 85(0.25)x
f(x) = (85 – 0.25)x

Answer 1

Each owner leaves the book worth 75% of its previous value, so the resale value after x owners is 85*(0.75)^x. That corresponds to f(x) = 85(1 − 0.25)^x (the first choice).