1/(2×4)+1/(4×6)+1/(6×8)+1/(8×10)+···+1/(2006×2008)
1/(2*4)+1/(4*6)+1/(6*8)+········+1/(2006*2008)等于?
计算1/2×4+1/4×6+1/6×8+···+1/2006×2008
计算:(1-2)·(3-4)·(5-6)…(2005-2006)·(2007-2008)
1/2*4+1/6*8+······+1/2006*2008+1/4*6+1/8*10+······+1/2004*20
计算:1+(-2)+3+(-4)+···+2005+(-2006)+2007+(-2008).
计算1+2-3-4+5+6-7-8+······+2005+2006-2007-2008+2009
成语归类(填序号)1·身临其境 2·引人入木 3·名副其实 4·自相矛盾 5·排山倒海 6·刻舟求剑 7·掩耳盗铃 8·
1+(-2)+3+(-4)+5+(-6)+···+2007+(-2008)+2009+(-2010)+2011+(-20
计算 1-2+3-4+5-6+····+(-1)^n+1*n
巧算(1+3+5+7······+995+997+999)-(2+4+6+8+10·····992+994+996+99
(1+1/2)(1-1/3)(1+1/4)(1-1/5)··········(1-1/2005)(1+1/2006)=_
求(2+5+8······+2000)-(1+4+7······+1999)的值.【简算】