Given the expression :
[tex]2\sqrt{3}\times\sqrt{12}[/tex]the answer will be as following :
[tex]\begin{gathered} 12=2\cdot2\cdot3=2^2\cdot3 \\ \sqrt[]{12}=\sqrt[]{2^2\cdot3}=2\sqrt[]{3} \end{gathered}[/tex]So,
[tex]2\sqrt[]{3}\cdot\sqrt[]{12}=2\sqrt[]{3}\cdot2\sqrt[]{3}=2\cdot2\cdot\sqrt[]{3}\cdot\sqrt[]{3}=4\cdot3=12[/tex]12 is a rational number