Answer:
84
Step-by-step explanation:
f(1)=4^1 - 1 = 3
f(4) = 4^4 - 1 = 255
rate of change =
(255 - 3) / (4 - 1) = 252 / 3 = 84
3/6 7 times
5n
it's 5 times N. So it's 5×N, but with Algebra you don't necessarily need to include the multiplication sign