Exercice \( 1 / \) Calculer les expressions suivantes en donnant les étapes de calcul. Exprimer ces résultats sous leur forme d'écriture scientifique. \[ A=-5 \times 15^{-1}+4^{2}: 5 \] \( B=40 \times 10^{12} \times 11 \times 10 \)

Expand the logarithm fully using the properties of logs. Express the final answer in terms of \( \log x \). \[ \log 8 x^{3} \] Answer Attempt 1 out of 2

\[ S_{n}=1+2+3+\cdots+n \] Calcule \( S_{278} \)

What is \( \sqrt[3]{27} ? \) \( \square \)

1. Choose the correct answer from the given ones : \( \begin{array}{llll}\text { 1 If } X=\{2\}, Y=\{3,4\} \text {, then } n\left(X^{2}\right) \times \mathrm{n}(\mathrm{Y})=\ldots \ldots \ldots \ldots \\ \begin{array}{llll}\text { (a) } 1 & \text { (b) } 2 & \text { (c) } 3 & \text { (d) } 4\end{array}\end{array} \).

3 The middle proportional between the two numbers 3 and 12 is ............. \( \begin{array}{llll}\text { (a) } \pm 3 & \text { (b) } \pm 4 & \text { (c) } \pm 6 & \text { (d) } \pm 12\end{array} \)