如题所述
第1个回答 2011-04-10
(1)99X99+199
=99x(100-1)+200-1
=9900-99+200-1
=9900+101-1
=10000
(2) 999X999+1999
=999x(1000-1)+2000-1
=999000-999+2000-1
=999000+1001-1
=1000000本回答被提问者采纳
=99x(100-1)+200-1
=9900-99+200-1
=9900+101-1
=10000
(2) 999X999+1999
=999x(1000-1)+2000-1
=999000-999+2000-1
=999000+1001-1
=1000000本回答被提问者采纳