If f(1)=10 and f(n)=3f (n-1) -n then find the value of f(5)

Question

If f(1)=10 and f(n)=3f (n-1) -n then find the value of f(5)

Answer 1

f(1) = 10

f(2) = = 3(f(1) - 2 = 3(10) - 2 = 28

f(3) = 3f(2) - 3 = 3(28) - 3 = 84- 3 = 81

f(4) = 3f(3) - 4 = 3(81) - 4 = 243-4 = 239

f(5) = 3f(4) -5 = 3(239) -5 = 717-5 = 712