For the polynomial 6xy2 – 5x2y? + 9x2 to be a trinomial with a degree of 3 after it has been fully simplified, the missing exponent of the y-term must be

Missing exponent of y term is one.

Step-by-step explanation:

The given polynomial is a trinomial with a degree of 3.That means we have to check the degree of each component of sum.

Degree of = 1+2 =3

Degree of = 2+n

Degree of =2

Now it's a polynomial with a degree of 3

Therefore 2+n =3 ⇒n =1