(căn 6+căn 5)mũ 2 -căn 120

$(\sqrt{6}+\sqrt{5})^2-\sqrt{120}$

$=(\sqrt{6})^2+2\sqrt{6}.\sqrt{5}+(\sqrt{5})^2-\sqrt{4.30}$

$=6+2\sqrt{30}+5-2\sqrt{30}$

$=6+5$

$=11$