[tex]\sqrt{1250} = \sqrt{625\cdot2} =\sqrt{625}\cdot\sqrt{2} = 25\sqrt{2}\\\\\sqrt[3]{1250} = \sqrt[3]{125\cdot10} = \sqrt[3]{125}\cdot\sqrt[3]{10} = 5\sqrt[3]{10}\\---------------------\\\\\frac{3}{7} = \frac{3}{7}\cdot\frac{\sqrt{7}}{\sqrt{7}} = \frac{3\sqrt{7}}{7}\\---------------------\\\\\sqrt{20\frac{1}{4}} = \sqrt{\frac{20\cdot4+1}{4}} = \sqrt{\frac{81}{4}} = \frac{9}{2} = 4\frac{1}{2} = 4,5[/tex]
[tex](\sqrt[3]{0,2})^{3} = 0,2\\\\-\sqrt{2\frac{7}{9}} = -\sqrt{\frac{2\cdot9+7}{9}} = -\sqrt{\frac{25}{9}} = -\frac{5}{3}} = -1\frac{2}{3}[/tex]
