Folosim urmatoarea formula:
[tex](a+b)^{2}=a^{2}+2ab+b^{2}[/tex]
[tex][(\sqrt{2} +\sqrt{5} )^{2} ]=(\sqrt{2} )^{2}+2*\sqrt{2}*\sqrt{5}+(\sqrt{5} )^{2}=2+2\sqrt{10}+5=7+2\sqrt{10}[/tex]
[tex][(\sqrt{5}+\sqrt{6} )^{2} ]=(\sqrt{5} )^{2}+2*\sqrt{5}*\sqrt{6} + (\sqrt{6} )^{2}=5+2\sqrt{30} + 6= 11+2\sqrt{30}[/tex]
