$\text{a)}\sqrt{90}:\sqrt{10}=\sqrt{90:10}=\sqrt{9}=3$

$\text{b)}\sqrt{0,18}:\sqrt{2}=\sqrt{0,18:2}=\sqrt{0,09}=0,3$

 

$\text{c)}\sqrt{14}:\sqrt{\frac{7}{8}}=\sqrt{14:\frac{7}{8}}=\sqrt{{\sout{14}}^2\cdot \frac{8}{{\sout{7}}^1}}=\sqrt{2\cdot 8}=\sqrt{16}=4$

 

$\text{d)}\sqrt{\frac{3}{4}}:\sqrt{12}=\sqrt{\frac{3}{4}:12}=\sqrt{\frac{{\sout{3}}^1}{4}\cdot \frac{1}{{\sout{12}}^4}}=\sqrt{\frac{1}{16}}=\frac{1}{4}$

 

$\text{e)}\sqrt[3]{135}:\sqrt[3]{5}=\sqrt[3]{135:5}=\sqrt[3]{27}=3$

 

$\text{f)}\sqrt[3]{72}:\sqrt[3]{9}=\sqrt[3]{72:9}=\sqrt[3]{8}=2$