Answer:
Step-by-step explanation:
Notice that when x = 0, f(x) = 18. Therefore we have already eliminated choices (a) and (c) and need to pick one from (b) and (d).
Look at (b): f(x) = 18(6/5)^x. If x = 1, f(x) = f(1) = 18(6/5)^1 = 21.6 or 21 6/10 or 21 3/5. Does this agree with the table? Yes. So (b) is the correct choice.
