Question

tính nhanh giá trị: 2005x2004-1/2003x2005+2004

Answer 1

2005 x 2004 - 1/2003 x 2005 + 2004

=2004 x ( 2005 + 1 ) - ...?

Answer 2

= 2005 x ( 2003 + 1 ) - 1/ 2003 x 2005 + 2004

= 2005 x 2003 + 2005 x 1 - 1/ 2003 x 2005 + 2004

= 2005 x 2003 + 2005 -1/ 2003 x 2005 + 2004

= 2003 x 2005 + 2004/ 2003 x 2005 + 2004

= 1 ( vì TS=MS)