\(P=\frac{1}{1007}+\frac{1}{1008}+.....+\frac{1}{2012}+\frac{1}{2013}\)
\(P=\left(1+\frac{1}{2}+\frac{1}{3}+....+\frac{1}{1006}+\frac{1}{1007}+\frac{1}{1008}+...+\frac{1}{2012}+\frac{1}{2013}\right)-\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{1006}\right)\)
\(P=\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{1006}+\frac{1}{1007}+\frac{1}{1008}+...+\frac{1}{2012}+\frac{1}{2013}\right)-2\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2012}\right)\)
\(\)
\(P=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...-\frac{1}{2012}+\frac{1}{2013}=S\)
Vậy (S-P)2013=0