Why is (n-1)(n+1)=n^2-1?
13.06.2025 03:05

And you are left with almost a square. One less than the square of side n.
The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2
The basic answer is that you cross-multiply the values in each factor:
How one of San Francisco's most successful new chains 'just kind of happened' - SFGATE
n^2 - n + n - 1
xx
xxx
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
xxx
xxx x
(n - 1)(n + 1)
xxxx
xxx x
I’m running away I live in Indiana what states near by are safe I’m 12 no comments?
So, that’s a rectangle with sides 2 and 4.
xxxx
Move the nub up to the top:
n^2 - 1