Why do we often use X as a variable?
Much of what we know about mathematics originated in Persia and Arabia. The word algebra literally comes from the Arabic word al-jabr which means “the reunion of broken parts.” When Spanish scholars were translating Arabic mathematical texts, they often came across the Arabic word shay-un which means “something.” Since Spanish doesn’t have the “sh” sound, they used the Greek letter chi (X) instead. Later, these Spanish texts were translated into Latin, X became the standard symbol for something we don’t know. So today we use the letter X because Spanish doesn’t have the “sh” sound.
https://cosmosmagazine.com/mathematics/why-x-marks-unknown-0
https://en.wikipedia.org/wiki/Algebra

The example of X becoming the standard variable in algebra is an example of how texts can change over time through various translations. The 8th Article of Faith says that “we believe the Bible to be the word of God as far as it is translated correctly.” The Lord revealed to Joseph Smith in the Joseph Smith Translation of the Bible many clarifications for scriptures in the Bible that had lost their original meaning due to changes or mistakes in translation. Some of this can be found in Joseph Smith-Matthew in the Pearl of Great Price.

1. Which of the following could be a variable? Select all that apply.
1. \(-1\)
2. y
3. A
4. 7.5
2. Which of the following represents multiplication? Select all that apply.
1. 4 × n
2. 4(n)
3. 4 + n
4. \(4\cdot\text n\)
5. 4n