\(A=\sqrt{10+6\sqrt{2}-2\sqrt{6}-2\sqrt{3}}-\sqrt{7-2\sqrt{6}}\)
\(A=\sqrt{1^2+\left(\sqrt{3}\right)^2+\left(\sqrt{6}\right)^2+2\sqrt{3.6}-2\sqrt{1.6}-2\sqrt{1.3}}-\sqrt{1-2\sqrt{6}+6}\)
\(A=\sqrt{\left(\sqrt{6}+\sqrt{3}-1\right)^2}-\sqrt{\left(\sqrt{6}-1\right)^2}\)
\(A=\sqrt{6}+\sqrt{3}-1-\left(\sqrt{6}-1\right)=\sqrt{3}\)