奥数的数学题!~

来源:百度知道 编辑:UC知道 时间:2024/06/06 20:48:05
555*13-111*15 2009分之2008*2010 55*(33分之1-44分之1)

这是三个式子吗?
555*13-111*15=555*13-111*(5*3)=555*13-555*3=555*(13-3)=555*10=5550;
(2008/2009)*2010=(2008*2010)/2009=(2009-1)*(2009+1)/2009
=2009-(1/2009)=4036080/2009;
55*(1/33-1/44)=5*11*1/33-5*11*1/44=5/3-5/4=5/12;
(注:2008/2009即是2009分之2008,第二个没有想到更好的方法啊,再考虑吧)

1.555×13-111×15 2. 2008/2009×2010
=111×5×13-111×15
=111×(5×13-15)
=111×(65-15)
=111×50
=5550

2. 2008/2009×2010
=4036080/4038090×2010
=4036080/2009
2008
=2008——
2009

3.55×(1/33-1/44)
=5/3-5/4
=5/12

①555×13-111×15
=111×5×13-111×15
=111×(5×13-15)
=111×(65-15)
=111×50
=5550
②2008/2009×2010
=4036080/4038090×2010
=4036080/2009
2008
=2008——
2009
③55×(1/33-1/44)
=5/3-5/4
=5/12

后面要是和我一样都是抄我的,我先答的!

2008/2009