[tex]\it a=\Big(\dfrac{3}{\sqrt3}+5\Big)\cdot\sqrt{27}-15\sqrt3=\Big(\dfrac{3}{\sqrt3}+5\Big)\cdot3\sqrt{3}-15\sqrt3=9+15\sqrt3-15\sqrt3=9\\ \\ \\ b=\Big(0,5+\dfrac{3}{4}\Big):1\dfrac{1}{4}+3=\Big(\dfrac{^{2)}1}{\ 2}+\dfrac{3}{4}\Big):\dfrac{5}{4}+3=\dfrac{5}{4}:\dfrac{5}{4}+3=1+3=4\\ \\ \\ m_g=\sqrt{a\cdot b}=\sqrt{9\cdot4}=3\cdot2=6[/tex]
