灵鹊做题网1/1*2+1/2*3+1/3*4+……+1/2004*2005+1/2005*2006 1/1*3+1/3*5+1/5
来源：学生作业帮 编辑：灵鹊做题网作业帮 分类：数学作业 时间：2024/07/02 20:54:44
1/1*2+1/2*3+1/3*4+……+1/2004*2005+1/2005*2006 1/1*3+1/3*5+1/5*7+……+1/49*51
1/1*2+1/2*3+1/3*4+……+1/2004*2005+1/2005*2006
=1-1/2+1/2-1/3+1/3-1/4+……+1/2005-1/2006
=1-1/2006
=2005/2006
1/1*3+1/3*5+1/5*7+……+1/49*51
=1/2*(2/1*3+2/3*5+2/5*7+……+2/49*51)
=1/2*(1-1/3+1/3-1/5-1/5-1/7+……+1/49-1/51)
=1/2*(1-1/51)
=25/51
=1-1/2+1/2-1/3+1/3-1/4+……+1/2005-1/2006
=1-1/2006
=2005/2006
1/1*3+1/3*5+1/5*7+……+1/49*51
=1/2*(2/1*3+2/3*5+2/5*7+……+2/49*51)
=1/2*(1-1/3+1/3-1/5-1/5-1/7+……+1/49-1/51)
=1/2*(1-1/51)
=25/51
1/1*2+1/3*4+1/4*5+...+1/2004*2005+1/2005*2006,
1+2+3+…+2004+2005+2006= 1+3+5+…+2001+2003+2005+2007
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)+(-3)+4+5+(-6)+(-7)+8+9+……+2004+2005+(-2006)+(-2007)+2
1+2-3-4+5…+2005+2006-2007-2008
2008-1+2006-3+2004-5+……+4-2005+2-2007等于几?
1+1/2+1/3+1/4+……+1/2004+1/2005+1/2006+1/2007+1/2008+1/2009+1
1-2+3-4+5-6…+2003-2004+2005-2006+2007的值是多少?
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
4/1*2*3+4/2*3*4+……+4/2004*2005*2006