1. So sánh
M = \(\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+...+\frac{1}{37\cdot38}\) và N = \(\frac{1}{20}+\frac{1}{21}+...+\frac{1}{38}\)
2. Cho :
S = \(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{2011}-\frac{1}{2012}+\frac{1}{2013}\)
P = \(\frac{1}{1007}+\frac{1}{1008}+...+\frac{1}{2013}\)
Tìm ( S - P )2013