Đáp án: $a)A=-1$
$b)B=\sqrt{ab}(a;b>0;a\neq b)$
Giải thích các bước giải:
`a)A=\frac{3\sqrt{2}-2\sqrt{3}}{\sqrt{3}-\sqrt{2}}-\frac{5}{\sqrt{6}-1}`
`=\frac{\sqrt{2}.\sqrt{3}(\sqrt{3}-\sqrt{2})}{\sqrt{3}-\sqrt{2}}-\frac{5(\sqrt{6}+1)}{6-1}`
`=\sqrt{2}.\sqrt{3}-(\sqrt{6}+1)`
`=\sqrt{6}-\sqrt{6}-1`
`=-1`
`b)B=\frac{a\sqrt{b}-b\sqrt{a}}{\sqrt{a}-\sqrt{b}}(a;b>0;a\ne b)`
`=\frac{\sqrt{ab}(\sqrt{a}-\sqrt{b})}{\sqrt{a}-\sqrt{b}}`
`=\sqrt{ab}`
