2x/1*3+2x/3*5+2x/5*7+……+2x/2003*2005=2x(1/1*3+1/3-5+1/5*7+-----+1/2003*2005)=x(1-1/3+1/3-1/5+1/5-1/7+-----1/2003-1/2005)=x(1-1/2005)=2004x/2005=2004 x=2004/(2004/2005)=2004*2005/2004=2005x=2005是原...