#### Answer

a polynomial

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
Use the description of a polynomial expression to evaluate if the given expression, $
2x^2+5x-20
,$ is a polynomial or not.
$\bf{\text{Solution Details:}}$
A polynomial expression is an expression where the exponent of the variable in every term is a nonnegative integer.
Using the description above, the given expression is $\text{
a polynomial
.}$