Đáp án+Giải thích các bước giải:
`f) \sqrt{\frac{3}{x}}`
`= \frac{\sqrt{3}}{\sqrt{x}}`
`= \frac{\sqrt{3x}}{x}`
`b) \frac{3}{\sqrt{10} + \sqrt{7}}`
`= \frac{3(\sqrt{10} - \sqrt{7})}{(\sqrt{10} + \sqrt{7})(\sqrt{10} - \sqrt{7})}`
`= \frac{3(\sqrt{10} - \sqrt{7})}{10 - 7}`
`= \sqrt{10} - \sqrt{7}`
`d) \frac{3}{1 - \sqrt{7}}`
`= \frac{3(1 + \sqrt{7})}{(1 - \sqrt{7})(1 + \sqrt{7})}`
`= \frac{3(1 + \sqrt{7})}{1 - 7}`
`= \frac{1 + \sqrt{7}}{2}`
`f) \frac{6}{\sqrt{6} - \sqrt{5}}`
`= \frac{6(\sqrt{6} + \sqrt{5})}{(\sqrt{6} + \sqrt{5})(\sqrt{6} - \sqrt{5})}`
`= \frac{6(\sqrt{6} + \sqrt{5})}{6 - 5}`
`= 6(\sqrt{6} + \sqrt{5})`
