Question

a computer valued at $1500 loses 20% of its value each year.
a) write a function rule that models the value of the computer.
b)find he value of the computer after 3 years.
c) In how many years will the value of the computer be less then $500

Answer 1

"Loses 20%" is the same as "Retains 80%". That should help.

Answer 2

\[f(n) = 1500 \times 0.8^{n}\]
f(3)=768
f(x)<500 -> x=5