If $1, \mathrm{\omega }, {\mathrm{\omega }}^2$ are the cube roots of unity, then
$(2-\mathrm{\omega })(2-{\mathrm{\omega }}^2)(2-{\mathrm{\omega }}^{10})(2-{\mathrm{\omega }}^{11})=$

$\begin{array}{rcl}{\mathrm{w}}^{10}& =& {\left({\mathrm{w}}^3\right)}^3.\mathrm{w}=\mathrm{w}, {\mathrm{w}}^{11}={\left({\mathrm{w}}^3\right)}^3.{\mathrm{w}}^2={\mathrm{w}}^2\end{array}$

$\begin{array}{rcl} & & (2-\mathrm{w}) (2-{\mathrm{w}}^2) (2-{\mathrm{w}}^{10}) (2-{\mathrm{w}}^{11})\end{array}$

$\begin{array}{rcl} & & (2-\mathrm{w}) (2-{\mathrm{w}}^2) (2-\mathrm{w}) (2-{\mathrm{w}}^2)\end{array}$

$\begin{array}{rcl} & =& {\left((2-\mathrm{w}) (2-{\mathrm{w}}^2)\right)}^2\end{array}$

$\begin{array}{rcl} & =& {(4-2{\mathrm{w}}^2-2\mathrm{w}+{\mathrm{w}}^3)}^2\end{array}$

${\left(5-2\left(\omega +{\omega }^2\right)\right)}^2=7^2=49$