Answer:
s(t) = 10000·1.65^t
Explanation:
The general form of an exponential model is ...
f(t) = (initial value) × (1 +(fractional change))^t
where the fractional change can be positive or negative and t is the number of time units. Each time unit will correspond to the period required for the fractional change.*
__
For your problem, you have (initial value) = 10,000 and (fractional change) = 65% = 0.65 with time units of 1 year. Your function for sales (s) will then be ...
s(t) = 10000·1.65^t
_____
* The business regarding time units has to do with problems where you get a description like "increased 30% in 4 hours." Then, if t is in hours, the multiplier of the initial value looks like 1.30^(t/4).