\(\sqrt{8-4\sqrt{3}}=\sqrt{6-2.\sqrt{6}.\sqrt{2}+2}=\sqrt{\left(\sqrt{6}-\sqrt{2}\right)^2}=\left|\sqrt{6}-\sqrt{2}\right|=\sqrt{6}-\sqrt{2}\)
\(\sqrt{9-6\sqrt{2}}=\sqrt{6-2\sqrt{6}.\sqrt{3}+3}=\sqrt{\left(\sqrt{6}-\sqrt{3}\right)^2}=\left|\sqrt{6}-\sqrt{3}\right|=\sqrt{6}-\sqrt{3}\)
\(\sqrt{8-4\sqrt{3}}=\sqrt{6}-\sqrt{2}\)
\(\sqrt{9-6\sqrt{2}}=\sqrt{6}-\sqrt{3}\)