Tricky Logic Puzzle with 26 Variables

[Tompson Lee]

Can you figure out what the answer of (x-a)(x-b)(x-c)...(x-z) is?
This problem seems very tricky and you might think you need to expand one by one, but if you think carefully, you will find out that the answer is very simple!

Solution:

Spoiler

[YOUTUBE]CnHBE4SbRRs[/YOUTUBE]

 

[Wilmer]

That's an old classic puzzle.

Spoiler

I remember someone programming a looper program
to solve this puzzle, but gave up saying:
"I give up: I keep getting zero no matter what"!

 

[Monoxdifly]

Spoiler

I didn't realize that (x - x) until Denis McField gave the hint...

 

[Wilmer]

This trick puzzle is usually presented this way:

(a-n)*(b-n)*(c-n)* ... *(x-n)*(y-n)*(z-n) = ?

Using "n" makes it look more authentic,
since "n" is part of most sequence formulas.