In math, y is generally used as an unknown variable. we use y as a variable just like x . x is also used as a variable in algebra

‘ y ‘ holds the place of a number that we may not know just yet in pre-algebra. We use this symbol when we don’t know how many we have of something or when the number of them can change.

y + 4 means we add 4 to whatever we decide y stands for. y could be any number, so we’re just holding its place with the variable

## Why are X and Y used in algebra?

In short, it is the English (or Latin) version of the Greek letter χ (chi), which was the first letter of the transliteration of the Arabic word for ‘something’, which was used in the original algebra texts. Since x was commonly used for one unknown, it made sense to use y as a second, and z as a third unknown.