(i) On the axes, sketch the graphs of \(y=|2x-5|\) and \(9y=80x-16x^2\).

(ii) Solve \(|2x-5|=4\).

(iii) Hence show that the graphs of \(y=|2x-5|\) and \(9y=80x-16x^2\) intersect at the points where \(y=4\).

(iv) Hence find the values of \(x\) for which \(9|2x-5|\le 80x-16x^2\).