Contains variables raised only to nonnegative integer exponents
Has no variables in denominators
Has no variables under radicals
Has no variables as exponents
Uses only addition, subtraction, and multiplication
May have constants
May have one or more terms
Each term is a product of a constant and variables with nonnegative integer powers
Examples include expressions like 3x^2 – 5x + 7 and 4a^3b – 2ab + 1