[tex]\displaystyle\bf\\1)\\\\\frac{2}{3} \sqrt{63} =\sqrt{\Big(\frac{2}{3}\Big)^{2} \cdot 63 }=\sqrt{\frac{4}{9}\cdot 63 }=\sqrt{28} \\\\\\2)\\\\\frac{1}{2} \sqrt{104} =\sqrt{\Big(\frac{1}{2}\Big)^{2} \cdot 104 }=\sqrt{\frac{1}{4}\cdot 104 }=\sqrt{26}\\\\\\28 > 26 \ \ \ \Rightarrow \ \ \ \sqrt{28} > \sqrt{26} \ \ \ \Rightarrow \ \ \ \boxed{\frac{2}{3} \sqrt{63} > \frac{1}{2} \sqrt{104}}[/tex]