1*2/1+2*3/1+3*4/1+.+2008*2009/1=?
1/1*2+1/2*3+1/3*4+1/4*5.+1/2007*2008+1/2008*2009=?
计算:|1/2-1|+|1/3-1/2|+|1/4-1/3|+...+|1/2009-1/2008|
初一数学题计算(-1*1/2)+(-1/2*1/3)=(-1/3*1/4)+...+(1/2008*1/2009)
1.|1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2009-1/2008|=
(-1*1/2)+(-1/2*1/3)+(-1/3*1/4)+.+(-1/2008*1/2009)+(-1/2009*1
|1/2-1|+|1/3-1/2|+1/4-1/3|+...|1/2009-1/2008|+|1/2010-1/2009
"1*2/1+2*3/1+3*4/1+.+2007*2008/1+2008*2009/1+2009*2010/1"这道题
(1-1/2)×(1-3/1)×.×(1-1/2008)×(1-1/2009)=?
计算:|1/2-1|+|1/3-1/2|+|1/4-1/3|+...+|1/2008-1/2007|+|1/2009-1
(1+3+5+...+2009)-(2+4+6+...+2008)=?
1+2+3+4……+2008+2009+2010=?
1-2+3-4+5-6+...+2007-2008-2009=