计算:2009×2007-2006×2008+2008×2005-2006×2006答案是多少

计算:2009×2007-2006×2008+2008×2005-2006×2006答案是多少
计算:2009×2007-2006×2008+2008×2005-2006×2006答案是多少

计算:2009×2007-2006×2008+2008×2005-2006×2006答案是多少
2009×2007-2006×2008+2008×2005-2006×2006
=(2008+1)×(2008-1)--2006×2006-2008×(2006-2005)
=2008×2008-1-2006×2006-2008
=(2008+2006)×(2008-2006)-2008-1
=4014×2-2009
=8028-2009
=6019

2009×2007-2006×2008+2008×2005-2006×2006
=4032063-4028048+4026040-4024036
=6019

(2008+1)(2008-1)-2006×2008+2008×2005-2006×2006
=2008*2008-1-2006×2008+2008×2005-2006×2006
=2008*2007-2006*2006-1
=2008*(2006+1)-2006*2006-1
=2008*2+2008-1
=2008*3-1
=6023

2009×2007-2006×2008+2008×2005-2006×2006
=2009×2007+2008×(2005-2006)-2006×2006
=2009×2007-2008-2006×2006
=(2008+1)*(2006+1)-2008-2006×2006
=2008*2006+2008+2006+1-2008-2006×2006
=2006*(2008+1-2006)+1
=2006*3+1
=6019