Answer
\[x=-2\]
Work Step by Step
The equation \[\left[ {{\left( 3+6 \right)}^{2}}\div 3 \right]\cdot 4=-54x\].
Use the order of operations,
\[\begin{align}
& \left[ {{\left( 9 \right)}^{2}}\div 3 \right]\cdot 4=-54x \\
& \left[ 81\div 3 \right]\cdot 4=-54x \\
& 27\cdot 4=-54x \\
& 108=-54x \\
\end{align}\]
Divided both sides by \[-54\],
\[\begin{align}
& \frac{108}{-54}=x \\
& -2=x \\
\end{align}\]
Therefore, \[x=-2\]
