I don't understand any of the steps that were made in the book. So I will try and solve it on my own so please let me know where I am going wrong. The problem is in the paint document. The general Term for the infinite series given is n(n+1) where n is greater than one and integral. LHS we have: which has (k-1) terms n(n+1) + (n+1)(n+2) + (n+2)(n+3) +..... +(n+k)(n+k+1) and (n+k)(n+k+1) = n2 + (2k+1)n + k2 + k (I will use the coefficient of n to find the upper value of the variable M below) Expanding the LHS we and grouping like terms we have: = (k-1)n2 + [Ʃ(1+2M)]n + constant: Note: the second term [Ʃ(1+2M)]n M ranges from 0 to k. Now I have: constant + [Ʃ(constant+2M)]n + (k-1)n2 = A + B(n+1) + C(n+1)2 +...... I will stop here because my approach is getting to difficult. Can someone please help.