cred ca e o greseala de scriere undeva, la x sau la y este +4!
[tex]1) m_a=\frac{x+y}{2}=2\sqrt{5}\\
m_g=\sqrt{xy}=\sqrt{(2\sqrt{5}+4)(2\sqrt5}-4)}=\sqrt{20-16}=\sqrt{4}=2\\
m_h=\frac{2xy}{x+y}=\frac{2\cdot4}{4\sqrt{5}}=\frac{2}{\sqrt{5}}=\frac{2\sqrt{5}}{{5}}\\
2) x=12+4\sqrt{3}+1=13+4\sqrt{3}\\
y=13-4\sqrt{3}\\
m_a=13\\
m_g=\sqrt{169-48}=\sqrt{121}=11\\
m_h=\frac{2\cdot121}{26}=\frac{121}{13}[/tex]
