(2((√3)+(√5)))/((√5)-(√3))-2√15

[latex] \frac{2(\sqrt3+\sqrt5)}{\sqrt5-\sqrt3} -2\sqrt{15}= \frac{2(\sqrt3+\sqrt5)(\sqrt5+\sqrt3)}{(\sqrt5-\sqrt3)(\sqrt5+\sqrt3)} -2\sqrt{15}=\\\\= \frac{2(\sqrt5+\sqrt3)^2}{5-3} -2\sqrt{15}= \frac{2(5+2\sqrt5\cdot \sqrt3+3)}{2} -2\sqrt{15}=\\\\=8+2\sqrt{15}-2\sqrt{15}=8[/latex]