Which statement describes a polynomial?

• A. An expression that contains at least one variable and has no equals sign.
• B. A mathematical sentence that contains an equals sign.
• C. A mathematical expression that is the sum of a number of terms.
• D. A list of numbers separated by commas.

Answer: (C)

Polynomials are algebraic expressions formed by adding or subtracting terms, where each term is a coefficient times a variable raised to a nonnegative integer power. The description that fits best is a mathematical expression that is the sum of a number of terms, such as 4x^3 - 2x + 7, which shows several terms being combined with addition and subtraction. This kind of expression has no equals sign and is not simply a list of numbers. The other descriptions either refer to an equation (which includes an equals sign) or describe forms that aren’t necessarily polynomials.