A trinomial is a polynomial with three terms. The polynomial 9x²y - 6x - 5y² is a trinomial because it has three terms (9x²y, 6x and 5y²).
The degree of a polynomial is the highest degree of an individual term. The term 9x²y has a degree of 3, 6x has a degree of 1 and 5y² have a degree of two therefore 9x²y - 6x - 5y² have a degree of 3.
The polynomial 9x²y - 6x - 5y² is a trinomial with a degree of 3
