is a monomial (since it is all connected by multiplication) and since it is in the degree of 2, that makes it a quadratic.
-2 is a constant (since it doesn't have variables) and it is a monomial (since it is all connected by multiplication)
3x-9 is a binomial (since it has two terms, not connected by multiplication) and since it has x in the power of 1, that makes it a linear equation.
Finally, -6x + 9 is a trinomial (since it has 3 terms connected by either addition or subtraction) and since the degree of the polynomial is 2, that makes it a quadratic.
