An algebraic expression is a combination of constants, variables, and mathematical operations (such as addition, subtraction, multiplication, and division). These expressions do not include an equal sign, unlike equations, and are used to represent a value or a relationship between quantities. For example, the expression $3x + 5$ consists of the variable $x$, the constant $5$, and the operation of multiplication and addition. Here, $x$ can take different values, and the expression evaluates differently based on the value of $x$. If $x = 2$, then $3x + 5 = 3(2) + 5 = 6 + 5 = 11$.

Would you like more details or have any questions about this? Here are 5 related questions:

1. What is the difference between an algebraic expression and an equation?
2. How can we simplify algebraic expressions?
3. What are the terms in an algebraic expression?
4. Can algebraic expressions have more than one variable?
5. How are algebraic expressions used in real-life situations?

Tip: Always keep track of the operations involved in an expression to avoid errors during simplification or evaluation.