Given that \(\log_4 x=p\), find, in terms of \(p\),

(i) \(\log_4(16x)\),

(ii) \(\log_4\left(\dfrac{x^7}{256}\right)\).

(iii) Hence solve \(\log_4(16x)-\log_4\left(\dfrac{x^7}{256}\right)=5\), giving your answer correct to 2 decimal places.