1x1/2十1/2x1/3十1/3x1/4十…十1/98x1/99十1/99x1/100
问题描述:
1x1/2十1/2x1/3十1/3x1/4十…十1/98x1/99十1/99x1/100
答
1x1/2十1/2x1/3十1/3x1/4十…十1/98x1/99十1/99x1/100