Answer:
-16
Step-by-step explanation:
Anything written in the form of a(b) or (b)a means a × b:
(-4)4 means -4 × 4 which is -16 (a positive and a negative multiplied together make a negative).
Hope this helps!
F(x) = 20000 (1-0.15) power x
So
f(x) = 20000 (0.85) power x