Answer:
The standard form is
.
The coefficient is

Explanation:
What is Standard Form of Polynomial?
The standard form of a polynomial is a way of writing a polynomial such that the term with the highest power of the variables comes first followed by the other terms in decreasing order of the power of the variable
We are given the expression

and we have to convert to standard form
First multiply the constants together to get the coefficient:

There is only one m term which is m²
Multiply the two n terms to get

Therefore in standard form we get ( in decreasing order of exponents)

The coefficient is 3