\(\frac{3\sqrt{5}+5\sqrt{3}}{\sqrt{3}+\sqrt{5}}+\frac{3\sqrt{5}-5\sqrt{3}}{\sqrt{5}-\sqrt{3}}\)
\(=\frac{\sqrt{3}.\sqrt{5}.\left(\sqrt{3}+\sqrt{5}\right)}{\sqrt{3}+\sqrt{5}}+\frac{-\sqrt{3}.\sqrt{5}\left(\sqrt{5}-\sqrt{3}\right)}{\sqrt{5}-\sqrt{3}}\)
\(=\sqrt{15}-\sqrt{15}\)
\(=0\)