Why is (n-1)(n+1)=n^2-1?
Last Updated: 02.07.2025 10:32
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:
xxx
Who was most disrespectful today, Zelensky, Trump, or Vance? Give examples.
xxx x
xxxx
n^2 - 1
Why does Russia seem so angry over the US and UK missile strikes in Ukraine?
(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
xxxx
xxx x
Move the nub up to the top:
xxx
And you are left with almost a square. One less than the square of side n.
n^2 - n + n - 1
xx
Are you happy that soon we will never hear from Kamala Jones again?
So, that’s a rectangle with sides 2 and 4.