Suma:
[tex] \frac{1}{1*2} + \frac{1}{2*3} + \frac{1}{3*4} +...+ \frac{1}{2013*2014} =[/tex]
Vom desface astfel:
[tex] \frac{1}{1} - \frac{1}{2} + \frac{1}{2} - \frac{1}{3} + \frac{1}{3} - \frac{1}{4} +...+ \frac{1}{2013} - \frac{1}{2014} =\ \textgreater \ [/tex]
[tex]=\ \textgreater \ 1- \frac{1}{2014} [/tex]
[tex]= \frac{2014-1}{2014} [/tex]
[tex]= \frac{2013}{2014} [/tex]
