\(\sqrt{7+4\sqrt{3}}+\sqrt{13-4\sqrt{3}}\)
= \(\sqrt{2^2+2.2.\sqrt{3}+\left(\sqrt{3}\right)^2}+\sqrt{\left(2\sqrt{3}\right)^2-2.2\sqrt{3}.1+1^2}\)
= \(\sqrt{\left(2+\sqrt{3}\right)^2}+\sqrt{\left(2\sqrt{3}-1\right)^2}\)
= \(2+\sqrt{3}+2\sqrt{3}-1\) = \(3\sqrt{3}+1\)
\(\sqrt{7+4\sqrt{3}}+\sqrt{13-4\sqrt{3}}\)
\(=\sqrt{2^2+2.2\sqrt{3+\left(\sqrt{3}\right)^2}}+\sqrt{\left(2\sqrt{3}\right)^2+2.2\sqrt{3}+1^2}\)
\(=\sqrt{\left(2+\sqrt{3}\right)^2}+\sqrt{\left(2\sqrt{3}-1\right)^2}\)
\(=2+\sqrt{3}+2\sqrt{3}-1\)
\(=3\sqrt{3}+1\)
Chúc bạn học tốt!!!