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

13.06.2025 06:07

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

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

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Why can't the ISS take a picture of Earth and prove to the Flat Earth Society that Earth is not really flat?

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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

Why do people think Mirko is boring in My Hero Academia?

Move the nub up to the top:

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

n^2 - 1

Orchestral Music: How well synchronised in time do musicians have to be to sound as if they are playing together?

(n - 1)(n + 1)

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

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What does a passable feminine crossdresser look like?

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

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How did Neo defeat the architect at the end of The Matrix: Reloaded? Was it solely due to his belief in himself or were there other factors at play?

n^2 - n + n - 1