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

13.06.2025 11:57

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

n^2 - n + n - 1

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

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What are mean nicknames to call my sister? She is always so mean to me.

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

I just cannot wake up early, even if I sleep on time. What should I do?

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

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

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Why do older siblings always hate younger siblings?

n^2 - 1

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Why do I (45, male) feel like I'm crushing on a girl (19, female)?

(n - 1)(n + 1)

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

Move the nub up to the top:

See how the national debt grew to more than $36 trillion - The Washington Post

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