a) Tính S = \(\dfrac{2+2^2+2^3+...+2^{2017}}{1-2^{2017}}\)
b) Cho A = \(\dfrac{1}{2017}\)+ \(\dfrac{2}{2017^2}\) + \(\dfrac{3}{2017^3}\) + ... + \(\dfrac{2017}{2017^{2017}}\) + \(\dfrac{2018}{2017^{2018}}\)
Chứng minh tằng A < \(\dfrac{2017}{2016^2}\)
Nhanh lên nha chiều mình học rồi