For the given functions \( f \) and \( g \), find the indicated composition. \( f(x)=\frac{x-9}{3}, g(x)=3 x+9 ;(g \circ f)(x) \)

Exercice 1 1) Compléter avec l'un des symboles : \( \epsilon ; \notin ; \subset \) ou \( \notin \) \( \{0 ;-7 ; 12\} \ldots \ldots \mathbb{N}^{*} ; \frac{5 \pi-\pi}{2 \pi-\pi} \ldots . \mathbb{Q} ;\left\{-1 ; \frac{18}{6} ; \sqrt{36} ;-7\right\} \ldots . \mathbb{Z} ; \frac{7}{3} \ldots \ldots \) ID 2) donner l'écriture scientifique : \( A=\frac{4 \times 300^{2} \times\left(2 \times 10^{-6}\right)^{-2}}{(0.01)^{-3}} \)

\( \left(I^{\text {st }}\right. \) Session 2022) If the ratio between the fourth term from the beginning to the fourth term from the end in the expansion of \( \left(\frac{a}{x}+\frac{x}{a}\right)^{2 n} \) equals \( a^{4}: x^{4} \) , then \( n=\cdots \cdots \) \( \begin{array}{llll}\text { (a) } 2 & \text { (b) } 4 & \left.\text { (where } x \in \mathbb{R}^{*}, a \in \mathbb{R}^{*}\right)\end{array} \)

If the two middle terms in the expansion of \( (a x+b)^{2 n+1} \) are equal, then find \( x \) \( a=2 b \)

14. \( (2 a-7 b)(2 a+7 b)_{\mathrm{Ypx}} \)

Soient xety deux nombres reels tels que \( : x \leq \frac{1}{2}, y \geq \frac{3}{2} \) et \( x-2 y=5 \) On pose \( A=\sqrt{x^{2}+(x-1)^{2}+2 x(x-1)} \) et \( B=\sqrt{4 y^{2}+(2 y-3)^{2}+4 y(2 y-3)} \) 1) Montrer que : \( A=\sqrt{(2 x-1)^{2}} \) et \( B=\sqrt{\left(4 y-3 t^{2}\right.} \) 4) Simplifier Ies nombres \( A \) et \( B \) 8) Determiner la valeur numérique du nombre \( A+3 \) X