Question

Prove that 4^n -1 is divisible by 3 for all positive integers n.
-using the definition of divisibility,we can state the conjecture as follows:
sn-->4^n -1=3r for some integer r...
how did that step happen?^^

Answer 1

rivisible by "3" means a multiple of "3"

Answer 2

3 times something should give us "4^n-1"

Answer 3

ohhh! i was reading it wrong, my book is rather confusing. thanks :D

Answer 4

yw.