Variable
A variable is a symbol, commonly a letter such as $x$, $y$, or $z$, used to represent an unknown or changeable numerical value in a mathematical expression or equation.
Example
In the expression $3x + 5$, the letter $x$ is the variable.
A variable is a symbol, commonly a letter such as $x$, $y$, or $z$, used to represent an unknown or changeable numerical value in a mathematical expression or equation.
In the expression $3x + 5$, the letter $x$ is the variable.