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

13.06.2025 09:50

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

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

n^2 - n + n - 1

n^2 - 1

My waist finally looks like how it did before I had kids but I didn’t lose weight. Why am I still 15 lbs from my starting weight?

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

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

Why did Democrats echo that Joe Biden was greater than FDR and should be put on Mt Rushmore? Why did Democrats vote for Biden blindly in the primaries and deny he was mentally impaired? Was it the lying media, or are Democrats ignorant and gullible?

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

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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

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(n - 1)(n + 1)

Move the nub up to the top:

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How do you know when your skirt is too short?

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