What defines a binomial?

A binomial is defined as a polynomial that consists of exactly two terms. These two terms are typically separated by a plus or minus sign. For example, expressions like (3x + 4) and (x^2 - 5x) qualify as binomials because they clearly have two distinct terms.

In contrast, the other definitions do not match the characteristics of a binomial. A polynomial with one term is known as a monomial, while one with three terms is referred to as a trinomial. A polynomial with four terms simply increases the number of terms further, thus not fitting the definition of a binomial either. This distinct feature of having precisely two terms makes the definition clear and straightforward.