which of the following are not polynomials

Answer:
A, C, F.
Step-by-step explanation:
A polynomial consists of an expression that involves only non-negative integer exponents for the variable; in all of your cases, the variable is x.
So, expression A has a square root of x, that is a rational exponent.
Expression C has variables in the denominators, that is negative exponent.
Expression F has variable at the exponent.
Answer:
A, C and F.
Step-by-step explanation:
A is not a polynomial because it contains a square root.
C is not a polynomial because it contains division by a variable (7/2x).
F is not one also because the variable is in the exponent (5^4x).