[tex]\displaystyle a). \frac{2 \sqrt{3} }{3} - \frac{5}{ \sqrt{3} } = \frac{2 \sqrt{3} }{3} - \frac{5 \sqrt{3} }{3} =- \frac{\not3 \sqrt{3} }{\not3} =- \sqrt{3} \\ \\ b). \frac{1}{3 \sqrt{2} } + \frac{5 \sqrt{2} }{6} = \frac{ \sqrt{2} }{6} + \frac{5 \sqrt{2} }{6} = \frac{\not6 \sqrt{2} }{\not6} = \sqrt{2}[/tex]
