<prompt> Acha x iwe nambari halisi, x 1. Kokotoasum_n 0infty frac1x2n - x-2n.  <response>: Tunaweza kuandikafrac1x2n - x-2n fracx2nx2n 1 - 1.Acha y x2n. Kishaanzaalignfracx2nx2n 1 - 1 fracyy2 - 1 fracy 1 - 1y2 - 1 fracy 1y2 - 1 - frac1y2 - 1 frac1y - 1 - frac1y2 - 1 frac1x2n - 1 - frac1x2n 1 - 1.endalignKwa hivyo, jumla ya darubini:sum_n 0infty frac1x2n - x-2n kushoto frac1x - 1 - frac1x2 - 1 kulia kushoto frac1x2 - 1 - frac1x4 - 1 kulia kushoto frac1x4 - 1 - frac1x8 - 1 kulia dotsb frac1x - 1. 