Prin raționalizare se obțin fracții cu numitor rațional:
[tex]h) \ \sqrt{\dfrac{8^{(4} }{20} } = \sqrt{\dfrac{2}{5} } = \dfrac{^{\sqrt{5} )} \sqrt{2} }{\sqrt{5}} = \dfrac{\sqrt{2} \cdot \sqrt{5} }{(\sqrt{5})^2} = \dfrac{\sqrt{10} }{5}[/tex]
[tex]j) \ \dfrac{\sqrt{12} }{\sqrt{40}} = \dfrac{\sqrt{2^2\cdot3} }{\sqrt{2^3\cdot5}} = \dfrac{2\sqrt{3} }{2\sqrt{10}} = \dfrac{^{\sqrt{10}) } \sqrt{3} }{\sqrt{10}} = \dfrac{\sqrt{3} \cdot \sqrt{10} }{(\sqrt{10})^2} = \dfrac{\sqrt{30} }{10}[/tex]
[tex]p) \ \dfrac{^{\sqrt{5}) } \sqrt{10} - \sqrt{2} }{4\sqrt{5}} = \dfrac{\sqrt{10} \cdot \sqrt{5} - \sqrt{2} \cdot \sqrt{5}}{4(\sqrt{5})^2} = \dfrac{\sqrt{50} - \sqrt{10}}{4 \cdot 5} = \dfrac{5\sqrt{2} - \sqrt{10}}{20}[/tex]
