Why is (n-1)(n+1)=n^2-1?
10.06.2025 07:07

n^2 - n + n - 1
So, that’s a rectangle with sides 2 and 4.
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
The Silent Virus Behind Mono Is Now a Prime Suspect in Major Diseases - Bloomberg
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:
And you are left with almost a square. One less than the square of side n.
Move the nub up to the top:
xxx x
n^2 - 1
3 Observations: Running Against the Wind; Isaiah Rodgers Nabs Interception - Minnesota Vikings
xxxx
(n - 1)(n + 1)
xxx
Patriots decline to say whether Stefon Diggs has passed key physical in contract - NBC Sports
xxx x
xxx
xxxx
Has your wife or girlfriend ever been felt up in public by a stranger?
xx