Thu gọn biểu thức:
\(A=\frac{\sqrt{45+27\sqrt{2}}+\sqrt{45-27\sqrt{2}}}{\sqrt{5+3\sqrt{2}}-\sqrt{5-3\sqrt{2}}}-\frac{\sqrt{3+\sqrt{2}}+\sqrt{3-\sqrt{2}}}{\sqrt{3+\sqrt{2}}-\sqrt{3-\sqrt{2}}}\)
\(B=\sqrt{\left(1-\sqrt{2020}\right)^2}.\sqrt{2021+2\sqrt{2020}}\)
\(C=\sqrt{\sqrt{3}-\sqrt{3-\sqrt{13-4\sqrt{3}}}}\)