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Why is (n-1)(n+1)=n^2-1?

10.06.2025 09:07

Why is (n-1)(n+1)=n^2-1?

The basic answer is that you cross-multiply the values in each factor:

So, that’s a rectangle with sides 2 and 4.

If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2

What are some cute stories with your crush?

n^2 - n + n - 1

xxxx

xxx x

If you believe in God, do you think God can save you from cancer?

And you are left with almost a square. One less than the square of side n.

xxxx

Move the nub up to the top:

Ray Dalio: ‘We should be afraid of the bond market’ - CNN

(n - 1)(n + 1)

xxx

xxx

Jessie J Diagnosed with ‘Early’ Breast Cancer: ‘I Need to Process It and Talk About It’ - Rolling Stone

xx

n^2 - 1

xxx x

— fri(end)s forever!

The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2