#### Answer

prime

#### Work Step by Step

Using the factoring of trinomials in the form $x^2+bx+c,$ the $\text{
expression
}$
\begin{array}{l}\require{cancel}
x^2-2x-5
\end{array} has $c=
-5
$ and $b=
-2
.$
There are no two numbers with a product of $c$ and a sum of $b.$ Hence, the given expression is not factorable or is $\text{
prime
.}$