Đáp án+Giải thích các bước giải:

 `a)`

`A=(\sqrt{32}+3\sqrt{18}):\sqrt{2}`

`=\sqrt{32}:\sqrt{2}+3\sqrt{18}:\sqrt{2}`

`=\sqrt{16}+3\sqrt{9}`

`=4+3.3`

`=4+9`

`=13`

Vậy `A=13`

`b)`

`B=\frac{\sqrt{15}-\sqrt{12}}{\sqrt{5}-2}-\frac{6+2\sqrt{6}}{\sqrt{3}+\sqrt{2}}`

`=\frac{\sqrt{3}.(\sqrt{5}-2)}{\sqrt{5}-2}-\frac{(6+2\sqrt{6}).(\sqrt{3}-\sqrt{2})}{(\sqrt{3})^{2}-2^{2}}`

`=\sqrt{3}-\frac{6\sqrt{3}-6\sqrt{2}+6\sqrt{2}-4\sqrt{3}}{3-2}`

`=\sqrt{3}-2\sqrt{3}`

`=-\sqrt{3}`

Vậy `B=-\sqrt{3}`

`c)`

`(\sqrt{12}-\sqrt{75}+\sqrt{48}):\sqrt{3}`

`=\sqrt{12}:\sqrt{3}-\sqrt{75}:\sqrt{3}+\sqrt{48}:\sqrt{3}`

`=\sqrt{4}-\sqrt{25}+\sqrt{16}`

`=2-5+4`

`=-3+4`

`=1`