[tex] \frac{1}{(2n-1) ^{2} (2n+1)}- \frac{1}{(2n-1)(2n+1) ^{2} } [/tex]= \frac{2}{(2n-1) ^{2} *(2n+1)^{2}} [/tex] \fr[tex] \lim_{n \to \infty} x_n = \lim_{n \to \infty} \frac{2}{1*3} + \frac{2}{3*5} +.........+ \frac{2}{(2n-1)(2n+1)} =[/tex][tex]= \lim_{n \to \infty}1- \frac{1}{3} + \frac{1}{3} - \frac{1}{5} +..........+ \frac{1}{2n-1} - \frac{1}{2n+1} = \lim_{n \to \infty} \frac{2n}{2n+1} =1[/tex]
