[tex]\displaystyle\\m_a=\frac{a+b}{2}=\frac{2-\sqrt{3}~~+~~2+\sqrt{3}}{2}= \frac{2+2}{2}=\frac{4}{2}=\boxed{\bf2}[/tex]
Exemplu:
[tex]\displaystyle\\x=3-\sqrt{5} \\y=3+\sqrt{5}\\\\m_a=\frac{3-\sqrt{5}+3+\sqrt{5}}{2} =\frac{3+3}{2}=3\in Q\\\\m_g=\sqrt{(3-\sqrt{5})(3+\sqrt{5})}=\sqrt{9-5}=\sqrt{4}=2\in Q[/tex]
