Why do we use letters like x and y to represent numbers in algebra?
In: Mathematics
The magic of algebra is that we can “do math” using placeholders for different quantities in our equations and it actually still works!
We don’t *need* to use letters as the placeholders, we totally *could* do things like the following:
> 4×(Something)-8=12
> 4×🤔-8=12
However, writing out “(Something)” over and over again would get really tedious and make your hand cramp up, and drawing a little symbol or emoji over and over isn’t much better… on the other hand:
> 4×S-8=12
writing single letters like “S” is super easy.
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As for *”Why ‘x’ all the time?”* that’s a quirk of history.
Just like how in my example above I used a single letter “S” to abbreviate the “Something” placeholder, the original Algebra textbooks basically used “Thing” as their placeholder word… but in Arabic the word for “Thing” starts with “x” and so “Solve for x.” simply means “Solve for (Thing)”.
When Europeans started learning Algebra and making translations of the Arabic books, they kept using “x”. Maybe because they missed the fact that it was basically an abbreviation, or maybe just because x is just so nice and easy to write.
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