[tex]\it a)\ \ m_a=\dfrac{2\sqrt3+5\sqrt2+\sqrt2-2\sqrt3}{2}=\dfrac{6\sqrt2}{2}=3\sqrt2\\ \\ \\ b)\ \ m_a=\dfrac{3\sqrt5+\sqrt6+5\sqrt6-\sqrt5}{2}=\dfrac{2\sqrt5+6\sqrt6}{2}=\dfrac{2(\sqrt5+3\sqrt6)}2{=\sqrt5+3\sqrt6} \\ \\ \\ d)\ m_a=\dfrac{\sqrt7+2\sqrt3+4\sqrt3-\sqrt7}{2}=\dfrac{6\sqrt3}{2}=3\sqrt3\\ \\ \\f)\ m-a=\dfrac{\sqrt2+3\sqrt3+\sqrt3-\sqrt2+\sqrt3}{2}=\dfrac{5\sqrt3}{2}\\ \\ \\ g)\ \ m_a=\dfrac{\sqrt3-\sqrt2-3\sqrt2+\sqrt2}{2}=\dfrac{\sqrt3-3\sqrt2}{2}\\ \\ \\ \underline{\underline{Obs.}}[/tex]
[tex]\it |\sqrt2-\sqrt3|=|\underbrace{\sqrt3-\sqrt2}_{>0}|=\sqrt3-\sqrt2[/tex]
