For this case we have that by definition, the standard form of a polynomial is given by:

Where:
x: It is the variable
a, b, c, d, e, f: Are the coefficients of the polynomial
n, n-1,3,2,1: Are the exponents. n is the degree of the polynomial because it is the greatest exponent.
In this case we have the following polynomial:

We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.

The degree of the polynomial is 3.
Answer:

The degree of the polynomial is 3.