Logo

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

12.06.2025 13:58

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

n^2 - n + n - 1

xxxx

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

Why do flat Earthers still exist even though it is scientifically proven that the Earth is spherical?

n^2 - 1

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

(n - 1)(n + 1)

This Simple Lifestyle Change Could Help Lower Your Heart Attack Risk by Up to 61%, New Study Says - EatingWell

xxx

xxxx

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

More measles exposures are happening at airports and tourist destinations. Here’s what travelers need to know - CNN

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

xxx

xxx x

Former Charles Manson follower is recommended for parole - NBC News

xxx x

Move the nub up to the top:

xx

I am glad you enjoyed my pictures. Do you have any photos to share?

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