原式
=(99-97+1/99x97)+(97-95+1/97x95)+……+(3-1+1/3x1)
=(2+2+2+……+2)+1/2x(2/1x3+2/3x5+……+2/97x99)
=2x48+1/2x(1-1/3+1/3-1/5+……+1/97-1/99)
=96+1/2x(1-1/99)
=96+1/2x(98/99)
=96+49/99
=96又99分之49
原式
=(99-97+1/99x97)+(97-95+1/97x95)+……+(3-1+1/3x1)
=(2+2+2+……+2)+1/2x(2/1x3+2/3x5+……+2/97x99)
=2x48+1/2x(1-1/3+1/3-1/5+……+1/97-1/99)
=96+1/2x(1-1/99)
=96+1/2x(98/99)
=96+49/99
=96又99分之49