Why is (n-1)(n+1)=n^2-1?
11.06.2025 05:34

xxx x
n^2 - n + n - 1
xxx
xxxx
n^2 - 1
So, that’s a rectangle with sides 2 and 4.
CVS to shutter 5 pharmacies in New York amid closure of 271 stores nationwide - New York Post
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
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
ISS Research & Development Conference Cancellation - NASA Watch
The basic answer is that you cross-multiply the values in each factor:
Move the nub up to the top:
(n - 1)(n + 1)
Inside Ukraine’s audacious drone attack on Russian air bases - CNN
And you are left with almost a square. One less than the square of side n.
xx
xxx x
'Cheers' star's cause of death released - KSDK
xxxx