Why is (n-1)(n+1)=n^2-1?
11.06.2025 00:31

n^2 - 1
xxx x
xxxx
Your Brain Wrinkles Are Way More Important Than We Ever Realized - ScienceAlert
The basic answer is that you cross-multiply the values in each factor:
xxx
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
What are the most meaningful Jewish jokes that reveal insights about Jewish culture?
n^2 - n + n - 1
And you are left with almost a square. One less than the square of side n.
So, that’s a rectangle with sides 2 and 4.
xxx x
xxxx
xxx
401(k) millionaires fell in the first quarter — but it’s not all bad news - MarketWatch
Move the nub up to the top:
The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2
xx
Rays star Wander Franco hit with gun charge amid sexual abuse trial - New York Post
(n - 1)(n + 1)