3. Factorise each of the following. \( \begin{array}{ll}\text { (a) } a^{2}-9 & \text { (b) } 49 b^{2}-1 \\ \text { (c) } 36 c^{2}-25 d^{2} & \text { (d) } 4 m^{2}-121 n^{2} \\ \text { (e) } 18 u^{2}-50 v^{2} & \text { (f) } 45 x^{2}-320 y^{2}\end{array} \)

\( \left. \begin{array} { l } { - x + y = 3 } \\ { y = 3 - x } \\ { y = x - 3 } \end{array} \right. \)

\( 2 x - \frac { 16 x + 1 } { 5 ^ { x + 1 } } + 1 = 0 \)

6. The total revenue of a magic show is \( 16,360 \mathrm{EGP} \). If each adult ticket to nttend the show cost 12 EGP and each children ticket cost 2 EGP , then what is the number of tickets of each type sold if 3,480 tickets in all were sold? A. 930 adult tickets and 2,550 children tickets B. 940 adult tickets and 2,540 children tickets C. 955 adult tickets and 2,525 children tickets D. 960 adult tickets and 2,520 children tickets

Question 5 - of 19 step 1 of 1 \( z \) varies directly as the cube of \( x \) and inversely as \( y \). If \( z=237 \) when \( x=10 \) and \( y=2 \), find \( z \) if \( x=8 \) and \( y=3 \). Round your answer to two decimal places if necessary.

tinúa con el ejercicio de cramer \[ x=\frac{\left|\begin{array}{ll}5 & 3 \\ 27 & 7\end{array}\right|}{\left|\begin{array}{ll}5 & 3 \\ 4 & 7\end{array}\right|}=\frac{(5)(7)-(27)(3)}{(5)(7)-(4)(3)} \Rightarrow \frac{35-81}{35-12}= \] \( \begin{array}{l}a_{1} x+b_{1} y=c_{1} \\ a_{2} x+b_{2} y=c_{2}\end{array} \) \( \begin{array}{l}x+3 y=5 \\ x+7 y=27\end{array} \)