What are the letters in an algebraic expression referred to as?

In an algebraic expression, the letters represent quantities that can change and are typically called variables. Variables are essential in mathematics as they allow for the expression of general relationships and the formulation of equations. For example, in the expression (3x + 2), the letter (x) is the variable, which can take on different values. This contrasts with constants, which are fixed values (like the number 2 in this case), and coefficients, which are the numerical factors that multiply the variables (such as 3 in this expression). Terms are the individual parts of an expression separated by addition or subtraction; in this example, (3x) and (2) are both considered terms. Understanding the role of variables is crucial, as they form the foundation of algebraic concepts used in solving problems and modeling real-world situations.