Answer:
In this problem, I can not tell what is V, so I will answer it in a general way. 
A polynomial is something of the form: 
a*x^5 + b*x^4 + c*x^3 + d*x^2 + e*x + f 
a, b, c, d, e, and f are real numbers and constant. 
Where the degree of the polynomial is equal to the greatest power (in this case 5). 
You write: 
4x^2 + 3Vx + 5 
Now, if V is a real number, then we have that this is a polynomial of degree 2. 
Because we can write this as: 
4*x^2 + (3V)*x + 5 
So the answer is true. 
Now, if V is a variable or an operation, the answer will be false.