Đáp án:
Giải thích các bước giải:
c) `\frac{12}{3+\sqrt{3}}-\frac{6}{\sqrt{3}}+\frac{\sqrt{27}-3\sqrt{2}}{\sqrt{3}-\sqrt{2}}`
`=\frac{12(3-\sqrt{3})}{(3-\sqrt{3})(\sqrt{3}+3)}-\frac{6\sqrt{3}}{3}+\frac{3\sqrt{3}-3\sqrt{2}}{\sqrt{3}-\sqrt{2}}`
`=\frac{12(3-\sqrt{3})}{6}-2\sqrt{3}+\frac{3(\sqrt{3}-\sqrt{2})}{\sqrt{3}-\sqrt{2}}`
`=2(3-\sqrt{3})-2\sqrt{3}+3`
`=6-2\sqrt{3}-2\sqrt{3}+3`
`=9-4\sqrt{3}`
d) `(\sqrt{2+\sqrt{3}}-\sqrt{3+\sqrt{5}})^2`
`=(\sqrt{\frac{4+2\sqrt{3}}{2}}-\sqrt{\frac{6+2\sqrt{5}}{2}})^2`
`=(\sqrt{\frac{(\sqrt{3}+1)^2}{2}}-\sqrt{\frac{(\sqrt{5}+1)^2}{2}})^2`
`=(\frac{\sqrt{3}-\sqrt{5}}{\sqrt{2}})^2`
`=4-\sqrt{15}`
