2*3=1/6+1/ [3*(3+A)] 故 A=1
所以,2003*2004=1/(2003×2004)+1/(2004×2005)
= 1/2003-1/2004+1/2004-1/2005
=1/2003-1/2005
=2/(2003×2005)
2*3=1/6+1/ [3*(3+A)] 故 A=1
所以,2003*2004=1/(2003×2004)+1/(2004×2005)
= 1/2003-1/2004+1/2004-1/2005
=1/2003-1/2005
=2/(2003×2005)