(1/2+1/3+...+1/2006)(1+1/2+...+1/2005)-(1+1/2+...1/2006)(1/2
计算:(1/2+1/3+...1/2006)(1+1/2+1/3+...1/2005)-(1+1/2+...1/2006
计算:(1/2006-1)(1/2005-1)(1/2004)… (1/3-1)(1/2-1).
1/1*2+1/2*3+1/3*4+.+1/2004*2005+1/2005*2006
1*2/1+1/2*3+1/3*4...2004*2005/1+2005*2006/1+2006*2007/1
巧算:1×(1-1/2)×(1-1/3)×……×(1-1/2005)×(1-1/2006)×(1-1/2007)×(1-
(-1*1/2)+(-1/2*1/3)+(-1/3*1/4)+(-1/4*1/5)+""+(-1/2005*1/2006
1/1*2+1/3*4+1/4*5+...+1/2004*2005+1/2005*2006,
-1+2-3+4+...-2005+2006等于
1.计算(1/2006-1)(1/2005-1)(1/2004-1)…(1/2-1) ( / 分数线)
(1/2008-1)*(1/2007-1)*(1/2006-1)*...*(1/3-1)*(1/2-1)
计算:(1/2+1/3+1/4+…+1//2006)(1+1/2+1/3+…+1/2005)-(1+1/2+1/3+1/
1+2+3+.+2005+2006+2007+2006+2005+...+3+2+1等于多少?