21) A frame is 15 in by 25 in aud is of uniform widtls. The inside of the frame leaves \( 75 \% \) of the total area available for the picture. What is the width of the frame?

7. En cada ítem, estudiar la posición relativa entre las dos rectas dadas y graficar ambas en un mismo sistema de coordenadas cartesianas. a) \( \left\{\begin{array}{l}x=1-5 \lambda \\ y=2+3 \lambda \\ z=-5+\lambda\end{array}\left\{\begin{array}{l}x=1 \\ y=1 \\ z=\mu\end{array}(\lambda, \mu \in \mathbb{R})\right.\right. \)\( \quad \) b) \( \left\{\begin{array}{l}x=3+2 \alpha \\ y=1-\alpha \\ z=5\end{array} \quad\left\{\begin{array}{l}x=-1-6 \beta \\ y=3+3 \beta \\ z=5\end{array} \quad(\alpha, \beta \in \mathbb{R})\right\}\right. \)

7. En cada ítem, estudiar la posición relativa entre las dos rectas dadas y graficar ambas en un mismo sistema de coordenadas cartesianas. a) \( \left\{\begin{array}{l}x=1-5 \lambda \\ y=2+3 \lambda \\ z=-5+\lambda\end{array}\left\{\begin{array}{l}x=1 \\ y=1 \\ z=\mu\end{array}(\lambda, \mu \in \mathbb{R})\right.\right. \)

SULrt \( 5 \quad \) Sebuah mesin memproses minuman mengeluarkan \( 62.92 \mathrm{~m}^{3} \) minuman schari daripada sebuah tangki. Tangki itu mempunyai jejari 2.2 m dan tinggi 4 m . Diberi bahawa isipadu tangki, \( V \) berubah secara langsung dengan kuasa dua jejari, \( j \mathrm{~m} \) dan tinggi, \( t \mathrm{~m} \). A beverage processing machine produces \( 62.92 \mathrm{~m}^{3} \) of beverage per day from a tank. The tank has a radius of 2.2 m and a height of 4 m. Given that the volume of the tank, \( V \) varies directly with the square of the radius, \( j \) mand the height, \( t \mathrm{~m} \). (a) Ungkapkan \( V \) dalam sebutan \( j \) dan \( t \). Express \( V \) in terms of \( j \) and \( t \).

7. En cada ítem, estudiar la posición relativa entre las dos rectas dadas y graficar ambas en un mismo sistema de coordenadas cartesianas. a) \( \left\{\begin{array}{l}x=1-5 \lambda \\ y=2+3 \lambda \\ z=-5+\lambda\end{array}\left\{\begin{array}{l}x=1 \\ y=1 \\ z=\mu\end{array}(\lambda, \mu \in \mathbb{R})\right.\right. \) b) \( \left\{\begin{array}{l}x=3+2 \alpha \\ y=1-\alpha \\ z=5\end{array}\left\{\begin{array}{l}x=-1-6 \beta \\ y=3+3 \beta \\ z=5\end{array} \quad(\alpha, \beta \in \mathbb{R})\right.\right. \)

a. Determine the radius and the co-ordinates of the centre of the circle given by the equation \[ x^{2}+y^{2}+8 x-2 y+8=0 \] [5 marks] b. Find the point of intersection of the circle \( x^{2}+y^{2}-2 x-8 y-6=0 \) and the line \( x+y=2 \) c. Find the equation of the tangent and the length of the tangent to the circle \( 4 x^{2}+4 y^{2}-2 x+5 y-8=0 \) from the point \( (-4,4) \). 5 marks \( ] \) d. Given the circle \( (x-2)^{2}+(y+3)^{2}=16 \), sketch the graph of the circle. [5 marks]