Which of the following represents an expression?

An expression is a combination of numbers, variables, and operators (such as addition, subtraction, multiplication, and division) that does not include an equality sign. The expression represents a value but does not state that this value is equal to something else.

In this case, "5 + x" is an example of an expression because it combines a constant (5) and a variable (x) using the addition operator, illustrating an algebraic relationship without indicating equality.

On the other hand, "3 = 3" is a statement of equality, asserting that both sides are equal. "x - 2 = 5" also expresses an equation because it equates two algebraic terms. Lastly, "10" is simply a number; while it conveys a value, it does not involve variables or operations with them and thus does not qualify as an expression in the algebraic sense.

This clarification underscores how expressions function in mathematical contexts and distinguishes them from equations and simple numeric values.