Answer:
The degree of the polynomial is 4.
Step-by-step explanation:
Given:
Polynomial = 
To Find:
The degree of the polynomial = ?
Solution:
The degree of the polynomial is the highest degree in the polynomial expression.
Here, the degrees are  4, 2, 1
and the coefficients are  7 , 5 , 1
and the constant  term is -9
The Highest  among the degrees is 4
Thus the degree of the polynomial is  4