(-1/2)-(-1/3)-(+1/4)
(-1/2)-(-1/3)-(+1/4)
200*(1-1/2)*(1-1/3)*(1-1/4)*.*(1-1/100)
(1-1/2)*(1-1/3)*(1-1/4)*.*(1-1/1998)*(1-1999)
(1+2/1)(1+4/1)(1+6/1).(1+10/)(1-3/1)(1—5/1).(1-9/1)
(-3/4)+1/2;
(1+1/2)*(1+1/4)*(1+1/6)*...*(1+1/2008)*(1-1/3)*(1-1/5)*(1-1/
(-1×1/2)+(-1/2×1/3)+(-1/3×1/4)+…+(-1/2008×1/2009)
1,1,2,3,3,4,4,7,( ),( )
1)2)3)4)5)
(1,1,1).(2,4,8)...3Q
8+(-2)+(-4)+1+1+(-3)
一道奥数题,急救!(1+1/2+1/3+1/4)×(1/2+1/3+1/4+1/5)-(1+1/2+1/3+1/4+1/