a] [tex]\sqrt{7-\sqrt{9} } =\sqrt{7-3} =\sqrt{4} =2[/tex]
b]
[tex][\sqrt[3]{27} +\sqrt[3]{0,027} ]:1,1=[3+\sqrt[3]{\frac{27}{1000} } ]:1,1=[3+\frac{3}{10} ]:\frac{11}{10} =\\\\3\frac{3}{10} \cdot\frac{10}{11}=\frac{33}{10}\cdot \frac{10}{11}= \frac{3}{1} =3[/tex]
