1/1*2+1/2*3+1/3*4+1/4*5.+1/2007*2008+1/2008*2009=?
1/1*2+1/2*3+1/3*4+1/4*5.+1/2007*2008+1/2008*2009=?
1+2-3-4+5...+2005+2006-2007-2008+2009
"1*2/1+2*3/1+3*4/1+.+2007*2008/1+2008*2009/1+2009*2010/1"这道题
1-2+3-4+5-6+...+2007-2008-2009=
(-1)+(+2)+(-3)+(+4)+...(-2007)+(+2008)+(-2009)+(20010)=
计算:|1/2-1|+|1/3-1/2|+|1/4-1/3|+...+|1/2008-1/2007|+|1/2009-1
1/2009-1/2008|+|1/2008-1/2007|+|1/2007-1/2006|+.+|1/3-1/2|+|
|2009/1-2008/1|+|2008/1-2007/1|+|2007/1-2006/1|+.+|3/1-2/1|+
1-(1/2-1/3)-(1/3-1/4).-(1/2007-1/2008)=?
1分之1*2+1分之2*3+1分之3*4++1分之2007*2008+1分之2008*2009
1/2*1/3+1/3*1/4+1/4*1/5.+1/2008*1/2009怎么解?
1/2*3+1/3*4+1/4*5.+1/2008*2009