Answer:
4x
Step-by-step explanation:
The polynomial expression is in the form:
f(x) = aₙxⁿ + aₙ₋₁xⁿ⁻¹ + aₙ₋₂xⁿ⁻² +..... + a₀
Polynomial have one variable so,
6y² + 5x
7y² + 9x
are not polynomial
Also since 4x is satisfying the expression of polynomial, Thus it is only polynomial in the given set of options.
