What defines a monomial?

A monomial is defined as a single term that consists of a product of constants and variables raised to non-negative integer powers. This means that a monomial can include a numerical coefficient (a constant) alongside one or more variables, but it must not involve any addition or subtraction, nor can it contain more than one term.

For example, (3x^2) and (-5xy) are both monomials since they are products of constants and variables. The absence of operations such as addition or subtraction is crucial in this definition, making it distinct from polynomials, which can consist of multiple such terms added together.

In contrast, the key characteristics that define the incorrect answers help further clarify the definition: a sum of multiple variables involves more than one term and includes addition, while including symbols for addition directly contradicts the definition of a monomial. Having at least two different variables refers to a term containing multiple variables, which can form a monomial (such as (xy)), but that does not include the possibility of single-variable monomials (like (x)).