Why is (n-1)(n+1)=n^2-1?
Last Updated: 24.06.2025 00:35
xxx
The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2
xxxx
IPOs That Launched Like Rockets — and Those That Flew Straight Into a Wall - PYMNTS.com
Move the nub up to the top:
So, that’s a rectangle with sides 2 and 4.
n^2 - n + n - 1
And you are left with almost a square. One less than the square of side n.
xx
xxx x
watchOS 26 adds new wrist flick gesture for these Apple Watch models - 9to5Mac
xxxx
xxx x
n^2 - 1
(n - 1)(n + 1)
xxx
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
Julia DeVillers On Sign of Anal Cancer She Mistook For Menopause - TODAY.com
The basic answer is that you cross-multiply the values in each factor: