a) [tex]\frac{1}{\sqrt{3} } * \frac{\sqrt{3} }{\sqrt{3} } = \frac{\sqrt{3} }{3}[/tex]
b) [tex]\frac{3}{\sqrt{5} } * \frac{\sqrt{5}}{\sqrt{5}} = \frac{3\sqrt{5}}{5}[/tex]
c) [tex]\frac{5}{2\sqrt{7}} * \frac{\sqrt{7}}{\sqrt{7}} = \frac{5\sqrt{7}}{2*7} = \frac{5\sqrt{7}}{14}[/tex]
