Question

计算1/2000*2002+1/2002*2004+1/2004*2006+1/2006*2008+1/2008*201

Answer 1

原式=(（1/2000-1/2002）+(1/2002-1/2004)+(1/2004-1/2006)+(1/2006-1/2008)+(1/2008-1/2010))/2

=(1/2000-1/2010)/2

=5/2000*2010

=5/4020000

=1/804000