=(1/1*2-1/2*3)+(1*2/31/3*4)+……+(1/2003*2004-1/2004*2005)=1/1*2-1/2004*2005=2009009/4018020
2+2²+2³+....+2^10设S=2+2²+2³+....+2^10那么2S=2²+2³+。。。+2^10+2^11两式相减可得S=2^11-2所以2+2²+2³+....+2^10=2^11-2 2
