Respuesta :

Answer:

Step-by-step explanation:

In polynomials, variables will not have negative sign.

So,

[tex]26) 3n^{-2} + 2n + 23 \\\\28) 5x^{4}+\frac{1}{3x^{3}}\\\\29) \frac{5}{x^{n}}[/tex]are not polynomials