Why is (n-1)(n+1)=n^2-1?
11.06.2025 09:33
The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2
(n - 1)(n + 1)
Move the nub up to the top:
How do you emotionally react to when others seem to feel sorry for you?
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
n^2 - 1
xxxx
What is the cost of implementing synchronized traffic lights in a mid-sized city?
n^2 - n + n - 1
xxx
xxxx
So, that’s a rectangle with sides 2 and 4.
xx
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Why do people procrastinate and how can they stop?
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xxx x
And you are left with almost a square. One less than the square of side n.
What should I expect after a BBL surgery?
The basic answer is that you cross-multiply the values in each factor: