`a)` `(\sqrt{1/3}-\sqrt{4/3}+\sqrt{3}):\sqrt{3}`
`=(frac{\sqrt{1}}{\sqrt{3}}-frac{\sqrt{4}}{\sqrt{3}}+frac{3}{\sqrt{3}}):\sqrt{3}`
`=frac{2}{\sqrt{3}}:\sqrt{3}`
`=frac{2\sqrt{3}}{3} . frac{1}{\sqrt{3}}`
`=frac{2\sqrt{3}}{3\sqrt{3}}`
`=2/3`
`b)` `\sqrt{3-\sqrt{5}}:\sqrt{2}`
`=\sqrt{frac{3-\sqrt{5}}{2}}`
`=\sqrt{frac{2(3-\sqrt{5})}{2.2}}`
`=\sqrt{frac{6-2\sqrt{5}}{4}}`
`=\sqrt{frac{5-2\sqrt{5.1}+1}{4}}`
`=\sqrt{frac{(\sqrt{5}-1)^2}{4}}`
`=frac{\sqrt{(\sqrt{5}-1)^2}}{\sqrt{4}}`
`=frac{|\sqrt{5}-1|}{2}`
`=frac{\sqrt{5}-1}{2}` (do `\sqrt{5}-1>0)`
