2/15= 1/3 - 1/5
2/35 = 1/5 - 1/7
2/63 = 1/7 - 1/9
............................
2/9603 = 1/97 - 1/99
2/9999 = 1/99 - 1/101
adunam si obtinem:
S= 1/3 - 1/101 = 98/303
sper ca nu am gresit pe undeva
