[tex] \frac{3}{2 \sqrt{5} } = \frac{3}{2 \sqrt{5} } \times \frac{2\sqrt{5}}{2\sqrt{5}}= \frac{3\times 2\sqrt{5}}{2\sqrt{5} \times 2\sqrt{5}} =\frac{6\sqrt{5}}{4 \times (\sqrt{5})^2}\\\\=\frac{6\sqrt{5}}{4\times5}=\frac{6\sqrt{5}}{20} =\boxed{\bf{\frac{3\sqrt{5}}{10}}}}[/tex]
