The square of any odd number minus 1 is a multiple of 8. Why?

The square of any odd number minus 1 is a multiple of 8. Why?

Let this odd number be 2n + 1,
Then (2n + 1) & # - 1 = 4N (n + 1)
Because N and N + 1 are two adjacent numbers, one is odd and the other is even
So n (n + 1) can be decomposed into 2
So the odd square minus one is a multiple of eight
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