9709 P13 - Jun 2022 - Q3 - 5 marks
855
An arithmetic progression has first term 4 and common difference \(d\). The sum of the first \(n\) terms of the progression is 5863.
(a) Show that \((n-1)d=\dfrac{11726}{n}-8\). [1]
(b) Given that the \(n\)th term is 139, find the values of \(n\) and \(d\), giving the value of \(d\) as a fraction. [4]
