2008+2009×2007/2008×2009-1
问题描述:
2008+2009×2007/2008×2009-1
答
2008+2009×2007/2008×2009-1
=2008+2009/(2008×2009)×2007-1
=2008+2007/2008-1
=2007又2007/2008