Logo

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

12.06.2025 11:04

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

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.

xxx

Ask Ethan: What are the "first stars" in the Universe? - Big Think

xxx x

xxx

(n - 1)(n + 1)

Why doesn't speeding significantly decrease one’s commute time? I've done a lot of road trips and driving and have experimented by increasing speed by 10–20%, but somehow this never equates to arriving 20% sooner, even on clear roads.

xxxx

xx

xxx x

Why would Joseph Smith say that polygamy was God's law?

Move the nub up to the top:

So, that’s a rectangle with sides 2 and 4.

The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2

How do empaths destroy narcissists?

n^2 - n + n - 1

n^2 - 1

xxxx

Don’t Miss This Rare Chance to See the Milky Way’s Glowing Core - SciTechDaily

If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2