Sửa đề ~~
\(A=\sqrt{2+\sqrt{3}}.\sqrt{2+\sqrt{2+\sqrt{3}}}.\sqrt{2+\sqrt{2+\sqrt{2+\sqrt{3}}}}.\sqrt{2-\sqrt{2+\sqrt{3}}}\)
\(A=\sqrt{\left(2+\sqrt{3}\right).\left(2+\sqrt{2+\sqrt{3}}\right).\left(2+\sqrt{2+\sqrt{2+\sqrt{3}}}\right).\left(2-\sqrt{2+\sqrt{3}}\right)}\)
\(A=\sqrt{2+\sqrt{3}.\left(4-\left(2+\sqrt{3}\right)\right).\left(2+\sqrt{2}+\sqrt{2+\sqrt{3}}\right)}\)
\(A=\sqrt{2+\sqrt{3}.\left(4-2-\sqrt{3}\right).\left(2+\sqrt{2}+\sqrt{2+\sqrt{3}}\right)}\)
\(A=\sqrt{2+\sqrt{3}.\left(2-\sqrt{3}\right).\left(2+\sqrt{2}+\sqrt{2+\sqrt{3}}\right)}\)
\(A=\sqrt{\left(4-3\right).\left(2+\sqrt{2}+\sqrt{2+\sqrt{3}}\right)}\)
\(A=\sqrt{1.\left(2+\sqrt{2}+\sqrt{2+\sqrt{3}}\right)}\)
\(A=\sqrt{2+\sqrt{2}+\sqrt{2+\sqrt{3}}}\)