\( \left(I^{\text {st }}\right. \) 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 \( n=\cdots \cdots \) \( \begin{array}{llll}\text { (a) } 2 & \text { (b) } 4 & \left.\text { (where } x \in \mathbb{R}^{*}, a \in \mathbb{R}^{*}\right)\end{array} \)

\( 67.04 \mathrm{~cm}^{2}=\frac{\sqrt{269}}{2} h \) what is h ?

vantes: \( A(x)=x^{3}+x^{2}+x-3 \) \( B(x)=(2 x+1)^{3}-(x+1)^{3} \) \( C(x)=8 x^{3}-1+4(2 x-1) \) \( D(x)=9 x^{2}-4-7(3 x-2)(x+1) \) Exercice \( 34: \) Soit \( a \) et \( b \) deux noml non nuls. Calculer \( a^{-2} b\left(a^{2} b^{-1}\right)^{4} a^{-3} b^{2} \)

b) \( 2 x y-1=5 \) f) \( 3 x x-1=8 \)

\( 67.04 cm ^ { 2 } = \frac { \sqrt { 26 a } } { 2 } h \)

13 If \( \frac{a}{b}=\frac{b}{c}=2 \), then \( \frac{a}{c}=\ldots \ldots \ldots \ldots \) \( \begin{array}{lll}\text { (a) } 2 & \text { (b) } 4 & \text { (c) } 6\end{array} \)