原式=(102X102-101X103)/102X103+(104X104-103X105)/104X105+……+(109x109-108x110)/109x110
=1/102x103+1/103x105+……+1/109x110
=1/102-1/103+1/103-1/105+……+1/109-1/110
相抵得1/102-1/110=2/2805
原式=(102X102-101X103)/102X103+(104X104-103X105)/104X105+……+(109x109-108x110)/109x110
=1/102x103+1/103x105+……+1/109x110
=1/102-1/103+1/103-1/105+……+1/109-1/110
相抵得1/102-1/110=2/2805