[tex]\displaystyle\bf\\\sqrt{x^2+3}=3\sqrt{3}~~\Big|^2~~~(Ridicam~ecuatia~la~puterea~a~2-a)\\\\\Big(\sqrt{x^2+3}\Big)^2=\Big(3\sqrt{3}\Big)^2\\\\x^2+3=27\\\\x^2=27-3\\\\x^2=24\\\\x=\pm\sqrt{24}=\pm\sqrt{4\times6}=\pm2\sqrt{6}\\\\x_1=-2\sqrt{6}\\\\x_2=2\sqrt{6}[/tex]
