What is an expression?

What is an expression?

• A. A statement that uses an equals sign.
• B. A math phrase that does not include an equals sign.
• C. A ratio expressed as a fraction.
• D. A function relating two sets of data.

Answer: (B)

An expression is a math phrase made up of numbers, variables, and operations that can be evaluated to a value, but it does not state a relationship or equality. The key feature is that there is no equals sign. For example, 3x + 4 or -2y + 6 are expressions—you can substitute a value for the variable and simplify. If you see an equals sign, like 3x + 4 = 7, that’s an equation, which asserts a relationship between two sides. A ratio expressed as a fraction is a form that can be an expression, but the general idea of an expression is simply a single mathematical phrase without an equals sign. A function describes a rule linking inputs to outputs, not just a standalone phrase.

An expression is a math phrase made up of numbers, variables, and operations that can be evaluated to a value, but it does not state a relationship or equality. The key feature is that there is no equals sign. For example, 3x + 4 or -2y + 6 are expressions—you can substitute a value for the variable and simplify. If you see an equals sign, like 3x + 4 = 7, that’s an equation, which asserts a relationship between two sides. A ratio expressed as a fraction is a form that can be an expression, but the general idea of an expression is simply a single mathematical phrase without an equals sign. A function describes a rule linking inputs to outputs, not just a standalone phrase.