#### Answer

$1-\sqrt{5}$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
To simplify the the given expression, $
\dfrac{3-3\sqrt{5}}{3}
,$ find the $GCF$ of all the terms. Then, express all terms as factors using the $GCF.$ Finally, cancel the $GCF$ in all the terms.
$\bf{\text{Solution Details:}}$
The $GCF$ of the coefficients of the terms, $\{
3,3,3
\},$ is $
3
$ since it is the highest number that can divide all the given coefficients. Writing the given expression as factors using the $GCF$ results to
\begin{array}{l}\require{cancel}
\dfrac{3\cdot1-3\cdot1\sqrt{5}}{3\cdot1}
.\end{array}
Cancelling the $GCF$ in every term results to
\begin{array}{l}\require{cancel}
\dfrac{\cancel3\cdot1-\cancel3\cdot1\sqrt{5}}{\cancel3\cdot1}
\\\\=
\dfrac{1-1\sqrt{5}}{1}
\\\\=
1-\sqrt{5}
.\end{array}