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

14.06.2025 06:41

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.

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Do you think there will ever be a movie that features a line such as “You graduated at the top of your class in liberal arts, we need your help”?

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Move the nub up to the top:

Why are Democrats opposed to restrictions on contraception such as requiring people to be over 18 to buy contraception, banning mail order contraception, and requiring a prescription from a doctor?

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 - 1)(n + 1)

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

Why did it take seven days for troops with helicopters, equipment, supplies, food, and water to be dispatched to southeast storm zones?

n^2 - n + n - 1

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

n^2 - 1

What makes Nigerian scammers skilled at impersonating people? Is their success a result of intelligence or other factors?

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What are some great short jokes?

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