\(\text{Đặt }A=\sqrt{10+6\sqrt{2}}-\sqrt{10-6\sqrt{2}}\)
\(\Rightarrow A^2=10+6\sqrt{2}+10-6\sqrt{2}-2\sqrt{\left(10+6\sqrt{2}\right)\left(10-6\sqrt{2}\right)}\)
\(=20-2\sqrt{28}\Rightarrow A=\sqrt{20-2\sqrt{28}}\text{ hoặc }A=-\sqrt{20-2\sqrt{28}}\)
\(\text{Mà }A>0\left(\sqrt{20+6\sqrt{2}}>\sqrt{20-6\sqrt{2}}\right)\)
\(\text{Nên }A=\sqrt{20-2\sqrt{28}}\)