Why is (n-1)(n+1)=n^2-1?
Last Updated: 21.06.2025 06:26
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
If freedom of speech is absolute, how come it's not applied for private spaces and for the Internet?
xxxx
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
Move the nub up to the top:
What's the funniest thing you heard in a movie theater?
xxxx
xxx x
xxx
What are some best sources of great porn?
And you are left with almost a square. One less than the square of side n.
xx
n^2 - n + n - 1
Why is it that women are stronger than men nowadays?
(n - 1)(n + 1)
So, that’s a rectangle with sides 2 and 4.
xxx x
What are the coolest new smart home gadgets to upgrade your living space?
n^2 - 1