A/ 123 + ( 25) ( 75)   + ( 46) 89  =123+(-100)+ 43= 23 +43 = 66 B/29

1/ a/ 123 +

( 25) ( 75)

 

+

( 46) 89

=123+(-100)+ 43= 23 +43 = 66 b/29 . 47 + 53 . 29=29.(47 + 53) =29.100 = 2900 0,5đ