Question

If n is an odd integer, then show that n^2-1 is divisible by 8

Answer 1

let
the odd integer be 7
7^2=49
49-1=48
48 is divisible by 8 as 8*6=48
let
the odd integer be 5
5^2=25
25-1=24
24 is divisible by 8 as 8*3=24

Answer 2

Here is the answer

We take two positive integers of the form 4q+1 or 4q+3 because it will be easy for us to understand.