1/2*4+1/4*6+1/6*8+…﹢1/98*100

问题描述:

1/2*4+1/4*6+1/6*8+…﹢1/98*100

1/2*4+1/4*6+1/6*8+…﹢1/98*100
=(1/2-1/4+1/4-1/6+1/6-1/8+……+1/98-1/100)/2
=(1/2-1/100)/2
=49/200