Answer
$5x$
Work Step by Step
The $GCF$ of $
20
$ and $
15
$ is $
5
.$
The $GCF$ of $
x^2
$ and $
x^1
$ is $
x^1
.$
Hence, the $GCF$ of the given expressions, $
20x^2 \text{ and } 15x
,$ is
\begin{array}{l}\require{cancel}
5x^1
\\\\=
5x
.\end{array}