a)
\frac{2}{\sqrt6}=\frac{2*\sqrt6}{\sqrt6*\sqrt6}=\frac{2\sqrt6}{6}=\frac{\sqrt6}{3}
b)
\frac{1}{\sqrt7}=\frac{1*\sqrt7}{\sqrt7*\sqrt7}=\frac{\sqrt7}{7}
c)
\frac{2\sqrt6}{\sqrt3}=\frac{2\sqrt2*\sqrt3}{\sqrt3}=2\sqrt2
d)
\frac{4}{\sqrt5}=\frac{4*\sqrt5}{\sqrt5*\sqrt5}=\frac{4\sqrt5}{5}=\frac{4\sqrt5}{5}
e)
\frac{\sqrt3}{\sqrt5}=\frac{\sqrt3*\sqrt5}{\sqrt5*\sqrt5}=\frac{\sqrt{15}}{5}
f)
\frac{3}{2\sqrt2}=\frac{3*\sqrt2}{2\sqrt2*\sqrt2}=\frac{3\sqrt2}{2*2}=\frac{3\sqrt2}{4}
g)
\frac{4}{\sqrt[3]2}=\frac{4*\sqrt[3]4}{\sqrt[3]2*\sqrt[3]4}=\frac{4\sqrt[3]4}{\sqrt[3]8}=\frac{4\sqrt[3]4}{2}=2\sqrt[3]4
h)
\frac{1}{\sqrt[3]9}=\frac{1*\sqrt[3]3}{\sqrt[3]{3^2}*\sqrt[3]3}=\frac{\sqrt[3]3}{\sqrt[3]{27}}=\frac{\sqrt[3]3}{3}
i)
\frac{9}{\sqrt[4]4}=\frac{9}{(2^2)^{\frac{1}{4}}}=\frac{9}{2^{\frac{1}{2}}}=\frac{9}{\sqrt2}=\frac{9*\sqrt2}{\sqrt2*\sqrt2}=\frac{9\sqrt2}{2}
j)
\frac{2}{\sqrt[5]4}=\frac{2}{\sqrt[5]{2^2}}=\frac{2*\sqrt[5]{2^3}}{\sqrt[5]{2^2}*\sqrt[5]{2^3}}=\frac{2\sqrt[5]8}{\sqrt[5]{2^5}}=\frac{2\sqrt[5]8}{2}=\sqrt[5]8
k)
\frac{1}{\sqrt3*\sqrt[3]3}=\frac{1}{3^{\frac{1}{2}+\frac{1}{3}}}=\frac{1}{3^{\frac{5}{6}}}=\frac{\sqrt[6]3}{\sqrt[6]{3^5}*\sqrt[6]3}=\frac{\sqrt[6]3}{3}
l)
\frac{2}{\sqrt2*\sqrt[4]2}=\frac{2^1}{2^{\frac{1}{2}+\frac{1}{4}}}=2^{1-\frac{3}{4}}=2^{\frac{1}{4}}=\sqrt[4]2