Maths induction q (1 Viewer)

[Sien]

Prove 4^n +5^n +6^n is divisible by 15, if n is odd
This is what I did so far:
1. Show n=1 is true
4^1 + 5^1 +6^1 =15, divisible by 15
Therefore, n=1 is true
2. Assume n=k is true, k is odd
4^k +5^k +6^k, divisible by 15
4^k +5^k +6^k = 15M (M represents integer )
3. Show n=k+2 is true
*I subbed it in, ceebs writing it.
And I'm stuck... I think I'm overlooking something...

 

[buriza]

 

[dan964]

full working:
(only open if you have actually attempted)

 

[dan964]

full working: View attachment 32230
(only open if you have actually attempted)

(yes I forgot to remove the second line)