4. Extrae factores de los radicales y simplifica al máximo. \( \begin{array}{ll}\text { a) } 8 \sqrt{2}-\sqrt{32} & \text { c) } 2 \sqrt{48}-3 \sqrt{675}+\sqrt{588} \\ \text { b) } \sqrt{27}-\sqrt{12}+\sqrt{75} & \text { d) } \sqrt[3]{375}+\sqrt[3]{81}\end{array} \)

8. a) \( \operatorname{Add} \frac{7}{9+\frac{1}{6}}= \)

Exencice 1 - POLynesie 2001 Calculer le nombre B en détaillant les calculs. \[ B=\frac{10^{7} \times 10^{-3}}{10} \] On donnera le résultat sous la forme \( 10^{n} \).

\( \begin{array}{ll}\text { a) } 3 \sqrt{12}-5 \sqrt{27}+\sqrt{243}-\frac{1}{5} \sqrt{75} & \text { b) } \sqrt{14+\sqrt{7-\sqrt[4]{81}}}\end{array} \)

Express the repeating decimal number as a quotient of two integers. \( 4 . \overline{45} \) \( 4 . \overline{45}=\square \) (Simplify your answer. Type an improper fraction.)

[b] Simplify to the simplest form : \( \sqrt{125}-\sqrt[3]{250}+\frac{1}{2} \sqrt[3]{16}+\sqrt{20} \)