Answer:
I will set this up for you and you work the math.
f(n) = f(n - 1) + 3
n = 7
f(7) = f(7 - 1) + 3 = f(6) + 3
Do the same for f(6).
f(6) = f(5) + 3 ⇒
f(7) = f(5) + 3 + 3
Similarly,
f(5) = f(4) + 3 ⇒
f(7) = f(4) + 3 + 3 +3
Do you see the pattern emerging here? Keep going until you are down to
f(2) = f(1) + 3 = 6 + 3 = 9
Then carefully plug the intermediate answers into their proper place in
f(7) = f(6) + 3
Explanation:
recursive equation