$$\left[\begin{matrix} 1 & \frac{ 21 }{ 4 } & - \frac{ 11 }{ 4 } & -6 \\-2 & - \frac{ 21 }{ 2 } & \frac{ 11 }{ 2 } & 17 \\4 & 21 & -11 & -27 \end{matrix}\right]$$
$\left(\begin{matrix}1&\frac{21}{4}&-\frac{11}{4}&-6\\-2&-\frac{21}{2}&\frac{11}{2}&17\\4&21&-11&-27\end{matrix}\right)$
$\left(\begin{matrix}1&-2&4\\\frac{21}{4}&-\frac{21}{2}&21\\-\frac{11}{4}&\frac{11}{2}&-11\\-6&17&-27\end{matrix}\right)$
