[tex]\large\boxed{\begin{array}{l}\underline{\sf pelo\,teorema\,de\,Pit\acute agoras}\\\rm x^2+(3\sqrt{2})^2=(3\sqrt{11})^2\\\rm x^2+9\cdot2=9\cdot11\\\rm x^2+18=99\\\rm x^2=99-18\\\rm x^2=81\\\rm x=\sqrt{81}\\\rm x=9\end{array}}[/tex]
