(1/2+1/3.+1/2009)*(1+1/2+1/3..+1/2008)-(1+1/2+1/3..+1/2009)*(1/2+1/3..+1/2008)

(1/2+1/3.+1/2009)*(1+1/2+1/3..+1/2008)-(1+1/2+1/3..+1/2009)*(1/2+1/3..+1/2008) (1-1/2-1/3-...-1/2009)(1/2+1/3+1/4...+1/2010)-(1-1/2-1/3-...-1/2009-1/2010)(1/2+1/3...+1/2009) 1/2*1+1/3*2+1/4*3.+1/2009*2008=就是1/2+1/6+1/12+1/20+.+1/2009*2008 2009*（1-1/2009)*(1-1/2008)*(1-1/2007)*.*(1-1/2) 1+2+3...+2008+2009+2010该怎么简便运算 1/2009+2/2009+3/2009+.+2008/2009=? 计算 |1/2011-1/2010|+|1/2010-1/2009|+|1/2009-1/2008|+...+|1/3-1/2|+|1/2-1|计算 |1/2011-1/2010|+|1/2010-1/2009|+|1/2009-1/2008|+...+|1/3-1/2|+|1/2-1| (2011/1-1)(2010/1-1)(2009/1-1)…(3/1-1)(2/1-1) (1/2010-1)*(1/2009-1)*(1/2008-1)*...*(1/3-1)*(1/2-1)尽快. 1/2009+2/2009+3/2009+.+2008/2009=?1/2+1/4+1/8+1/16+.+1/1024=? (1-1/2^2)(1-1/3^2)(1-1/4^2).(1-1/2009^2), |1/2011-1/2010|+|1/2011-1/2009|+|1/2009-1/2008|+...+|1/3-1/2|+|1/2-1| ｜1/2-1｜+｜1/3-1/2｜+1/4-1/3｜+...｜1/2009-1/2008｜+｜1/2010-1/2009｜=? 1/(1*1+1)+1/(2*2+2)+1/(3*3+3)+……1/(2009*2009+2009) 答案是 (1-1/2)(1/3-1)(1-1/4)(1/5-1)``````(1/2009)(11/2010) 1.2009/1+2009/2+2009/3+.2009/2008= 2.2/1+4/1+8/1+16/1+.+1024/1=2009/1+2009/2+2009/3+.2009/2008= 2/1+4/1+8/1+16/1+.+1024/1= 1/1*2+1/2*3+...+1/2008*2009= 初中绝对值|1/2010-1/2009|+|1/2009-1/2008|+...|1/2-1|