Question

if n is an odd positive integer then show that n square-1 is divisible by 8

Answer 1

if n is odd positive integer , then let n = 3 ,5 ,9..... and so on..

so first let n=3
therefore n²=3²=9
n²-1=9-1=8 .which is divisble by 8

now let n=5
therefore n²=5²=25
n²-1=25-1=24. which is also divisible by 8


therefore any odd positive integer which has equation n²-1 is divisible by 8