Factorise \( \begin{array}{l} 4 p-24 p q-16 p r \text { completely } \\ =\end{array} \)

9. Malged the subject of the relation \( w=M \sqrt{\frac{\left(D^{2}+d^{2}\right)}{2 d^{2}}} \)

The sum of the first three terms of an arithmetic sequence is 15 and their product is 80. Determine the first threc terms.

Make \( d \) the subject of the relation in \[ W=M \sqrt{\frac{\left(D^{2}+d^{2}\right)}{2 d^{2}}} \]

The ratio between the sum of the fifth, sixth and seventh terms of a geometric series ind the sum of the first three terms of the same series is \( 81: 16 \). Determine the sum he first ten terms, if the first term is 1024 .

Show that if \( x^{2}-2 x<5 \) then \( x-1< \)