計算:(1/2006-1)(1/2005-1)(1/2004-1)……(1/3-1)(1/2-1)
计算:(1/2006-1)(1/2005-1)(1/2004)… (1/3-1)(1/2-1).
計算:1+2+3+...+2003+2004+2005+2006+2005+2004+2003+...+3+2+1=?
1.计算(1/2006-1)(1/2005-1)(1/2004-1)…(1/2-1) ( / 分数线)
巧算:1×(1-1/2)×(1-1/3)×……×(1-1/2005)×(1-1/2006)×(1-1/2007)×(1-
1+1/2+1/3+1/4+……+1/2004+1/2005+1/2006+1/2007+1/2008+1/2009+1
1+2+3+…+2004+2005+2006= 1+3+5+…+2001+2003+2005+2007
计算:(1/2+1/3+……+1/2006)(1+1/2+1/3+……+1/2005)-
1/1*2+1/2*3+1/3*4+.+1/2004*2005+1/2005*2006
(1/2005-1)(1/2004-1)(1/2003-1)…(1/2-1)=?
1/1*2+1/3*4+1/4*5+...+1/2004*2005+1/2005*2006,
计算:(1/2+1/3+1/4+…+1//2006)(1+1/2+1/3+…+1/2005)-(1+1/2+1/3+1/
计算:{1\2005-1/2004}+{1/2004-1\2003}+{1/2003-1/2002}+……+{1/3-1