Question

n2-1 is divisible by 8 if n is?

Answer 1

Any odd positive integer is of the form 4m + 1 or 4m + 3 for some integer m.
When n = 4m + 1,
⇒ n2 – 1 is divisible by 8.

Hence, n2 – 1 is divisible by 8 if n is an odd positive integer.

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