2008+2007×20092008×2009−1.
问题描述:
. 2008+2007×2009 2008×2009−1
答
,2008+2007×2009 2008×2009−1
=
,2008+2007×(2008+1) 2008×(2008+1)−1
=
,2008+2007×2008+2007 2008×2008+2008−1
=
,2008×2008+2007 2008×2008+2007
=1.