\begin{tabular}{l} Use the correct Math \\ Criteria \\ \hline Used correct Jls \\ \hline Lines ar. \\ \hline\end{tabular}

Montrer que: \( \frac{\left(9^{n+1}+9^{n}\right)^{2}}{\left(3^{2 n}-3^{8 n+1}\right)^{2}} \in \mathbb{Z} \)

1. \( 5^{x+1}+5^{x}+5^{x-1}=31 \)

4. Which law is also called as the elasticity law a) Bernoulli's law b) Stress law c) Hooke's law d) Poisson's law 5. The body will regain it is previous shape and size only when the deformation caused by the external forces, is within a certain limit. What is that limit? a) Plastic limit b) Elastic limit c) Deformation limit

tercice 5. Soit \( n \in \mathbb{N}^{*} \). On définit la relation \( \mathcal{R} \) sur \( \mathbb{C} \) par: \( z \mathcal{R} z^{\prime} \Leftrightarrow z^{n}=z^{\prime n} \) Montrer que \( \mathcal{R} \) est une relation d'équivalence. Soit \( \mathrm{a} \in \mathbb{C}^{*} \). Déterminer la classe d'équivalence de a note \( \mathrm{cl}(\mathrm{a}) \). En déduire les classes \( \mathrm{cl}(1+\mathrm{i}) \) et \( \mathrm{cl}(-1+i \sqrt{3}) \) pour \( \mathrm{n}=3 \) et \( \mathrm{n}=4 \).

ТЕОРия Какое из приведенных неравенств будет линейным неравенством с одной переменной: \( \square \) А) \( x \geq-4 \) \( \square \) В) \( x+1 \leq y \) \( \square \) C) \( 4+3<23 \) \( \square \) D) \( 3 x<-5 \) \( \square \) Е) \( x y \leq \frac{5}{6} \) \( \square \) F) \( y<9,7 \)