3/25+3/58+3/811+...+3/20092012

来源：学生作业帮助网编辑：作业帮时间：2024/11/17 17:37:30

3/2*5+3/5*8+3/8*11+...+3/2009*2012
3/2*5+3/5*8+3/8*11+...+3/2009*2012

3/2*5+3/5*8+3/8*11+...+3/2009*2012
3/2*5+3/5*8+3/8*11+...+3/2009*2012
=1/2-1/5+1/5-1/8+1/8-1/11+.+1/2009-1/2012
=1/2-1/2012
=(1006-1)/2012
=1005/2012