An algebraic expression is a combination of numbers, variables, and mathematical operations. For example, in the expression 3x + 5, x is a variable that can represent any number, while 3 and 5 are constants. Algebraic expressions are used to represent real-world situations, such as calculating the total cost of items or determining the area of a shape. These expressions can be simplified or manipulated using various rules of algebra. For instance, you can combine like terms, which are terms that have the same variable raised to the same power. Understanding algebraic expressions is essential for solving equations and tackling more complex mathematical problems.