hint on the induction step:
can you follow from here?
do you know how proofs by induction work? Mathematical induction - Wikipedia, the free encyclopedia
1. base case: n=1 ... f(1) = 20 is divisible by 4, base case verified.
2. inductive step: suppose the statement holds for some n. show that the statement holds for n+1. And that is what i've done in the previous post.
Sorry I'm being retarded. Yes I am meant to know how induction works :P I can do the simpler questions, this through me off as it had a n within the bracket as well as the power.
Yes, that makes perfect sense now! Thanks for your help, this has been bugging me!