Đáp án+Giải thích các bước giải:
`a)\frac{a+\sqrt{ab}}{b+\sqrt{ab}}`
`=\frac{\sqrt{a}^2+\sqrt{ab}}{\sqrt{b}^2+\sqrt{ab}}`
`=\frac{\sqrt{a}(\sqrt{a}+\sqrt{b})}{\sqrt{b}(\sqrt{b}+\sqrt{a})}`
`=\frac{\sqrt{a}}{\sqrt{b}}`
`b)\frac{\sqrt{10}-\sqrt{15}}{\sqrt{8}-\sqrt{12}}`
`=\frac{\sqrt{5}.\sqrt{2}-\sqrt{5}.\sqrt{3}}{2\sqrt{2}-2\sqrt{3}}`
`=\frac{\sqrt{5}(\sqrt{2}-\sqrt{3})}{2(\sqrt{2}-\sqrt{3})}`
`=\frac{\sqrt{5}}{2}`
`c)\frac{5+\sqrt{5}}{\sqrt{10}+\sqrt{2}}`
`=\frac{\sqrt{5}(\sqrt{5}+1)}{\sqrt{2}(\sqrt{5}+1)}`
`=\frac{\sqrt{5}}{\sqrt{2}}`
