\frac{5}{\sqrt3+\sqrt5}5√3+√5
=\frac{5}{\sqrt5+\sqrt3}=5√5+√3
=\frac{5(\sqrt5-\sqrt3)}{(\sqrt5+\sqrt3)(\sqrt5-\sqrt3)}=5(√5−√3)(√5+√3)(√5−√3)
=\frac{5(\sqrt5-\sqrt3)}{(\sqrt5)^2-(\sqrt3)^2}=5(√5−√3)(√5)2−(√3)2
=\frac{5(\sqrt5-\sqrt3)}{5-3}=5(√5−√3)5−3
=\frac{5}{2}(\sqrt5-\sqrt3)=52(√5−√3)