(2009+2007分之1)*2008分之1

问题描述:

(2009+2007分之1)*2008分之1

(2009+2007分之1)*2008分之1
=2009 / 2008 +1/(2007*2008)
=1+1/2008 + 1/(2007*2008)
=1+ 1/2008 +1/2007-1/2008
=1+1/2007

=2009 / 2008 +1/(2007*2008)
=1+1/2008 + 1/(2007*2008)
=1+ 1/2008 +1/2007-1/2008
=1+1/2007