1/1*2+1/2*3+1/3*4+1/4*5+.+1/2006*2007

1/1*2+1/2*3+1/3*4+1/4*5+.+1/2006*2007 2*1 1/2*1 1/3*1 1/4*1 1/5*.1 1/2006*1 1/2007 (1+1/2+1/3+...+1/2006)*(1/2+1/3+1/4+...1/2007)-(1+1/2+1/3+.. 巧算1/2*1/3+1/3*1/4+1/4*1/5+……+1/2006*1/2007+1/2007*1/2008 1+2-3-4+5…+2005+2006-2007-2008 计算题1-1/2-1/3+1/4+1/5-1/6-1/7+1/8+1/9……-1/2006-1/2007+1/2008+ 数学计算题：计算(1-1/2)*(1-1/3)*(1-1/4)*.*(1-1/2006)*(1-1/2007) 2006x2007+2007x2008+2008x2006-2/1+2+3+4+5'''''''+2006+2007 (-1*1/2)+(-1/2*1/3)+(-1/3*1/4)+(-1/4*1/5)+""+(-1/2005*1/2006 ①1/2+1/2*3+1/3*4+…+1/2006*2007= 1/2(x+1)+1/3(x+2)+1/4(x+3)+.+1/2007(x+2006)=2006 1/1*2+1/3*4+1/4*5+...+1/2004*2005+1/2005*2006,