College Algebra (11th Edition)

A polynomial is a term or finite sum of terms with only positive or zero integer exponents. -16$x^{5}y^{7}$ + 12$x^{3}y^{8}$ - 4x$y^{9}$ + 18$x^{10}$ is a polynomial but has four terms, so it is neither a monomial, binomial, nor trinomial. Its degree is 12 because the term with the largest degree is -16$x^{5}y^{7}$, and the degree is found by adding the exponents in the term: 5 + 7 = 12