What is a polynomial?

• A. A mathematical expression that uses variables and coefficients, connected through operations like adding, subtracting, multiplying, and exponentiation
• B. A number with one term
• C. A function with a domain of real numbers only
• D. A numeral with decimal digits

Answer: (A)

Polynomials are expressions built from numbers and a variable by adding, subtracting, and multiplying, with the variable raised to whole-number powers and coefficients being real numbers. This means you can have one term or many terms, as in 3x^2 + 2x - 5 or just 7. The key is that the variable powers are nonnegative integers and the terms are combined using addition, subtraction, and multiplication. That’s why the described choice fits best: it captures how polynomials are formed from variables, coefficients, and those operations. A single-term number describes only a monomial, not the full idea; a function with a real-number domain is about functions, not what a polynomial is; and a numeral with decimal digits is just a number, not an expression in variables.