What is a variable in algebra?

A variable is a letter or symbol used in algebra to represent a number that can change or is not yet known. Common variables include letters like x, y, or z. Variables allow us to create general rules and equations that apply to many situations. For example, if you don’t know the cost of one item, you can use a variable to write an equation to solve for it. Understanding variables is essential because they are the foundation for creating and solving equations and understanding relationships between numbers.