Answer:
C) f(x)=25(4/5)^x
Step-by-step explanation:
Observe that the exponential function is decreasing (so exponential decay). This means that r<1 making A and D wrong as they show exponential growth as r>1. Also notice that the y-intercept is 25 which is where the function crosses the y-axis when x=0. This means C is the only correct answer.
