Help please graded assignment

Question

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

Answer 1

Greetings! Lets solve this shall we ?

So, we must find the value of the fifth iteration given f(1) = 10 and f(n) = 3f(n-1) - n. After given the first term we can find the second term and the others such that

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

f(3) = 3f(3-1) - 3 = 3f(2) - 3 = 3(28) - 3 = 81

f(4) = 3f(4-1) - 4 = 3f(3) - 4 = 3(81) - 4 = 239

f(5) = 3f(5-1) - 5 = 3f(4) - 5 = ?

I hope this helped!

Answer 2

f(5) = 3f(5-1)-5 = 3f(4)-5

f(4) = 3f(4-1)-4 = 3f(3)-4

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

f(2) = 3f(2-1)-2 = 3f(1)-2 = 3x10 -2= 30-2=28

f(3) = 3x28 -3 = 84-3 = 81

f(4) = 3x81-4 = 243-4 = 239

f(5) = 3x239-5= 717-5 = 712