A variable is a quantity that may change within the context of a mathematical problem or experiment. Typically, we use a single letter to represent a variable. The letters x , y , and z are common generic symbols used for variables.
In mathematics, a variable is a letter that represents any number. Therefore, variables are often used to represent unknown numbers.
For example, the image I attached is a jar filled with coins. We can use "X" to represent the number of coins in the jar since we don't know how many there are.
