Question

Tính :

( - 57 ) . ( 67 - 34 ) - 67 . ( 34 - 57 ) 

= ............ - ( - 57 ) . 34 - [ 67 . 34 - 67 . 57 ]

= ..........................

= ........................

= ........................

Answer 1

(-57).(67-34)-67.(34-57)

=-(57.67)+(57.34)-(67.34)+(67.57)

=-(57.67)+(57.67)+(57.34)-(67.34)

=0+(57.34)-(67.34)

=34.57-34.67

​​​​​​=34.(57-67)

=34.(-10)

=-340

Answer 2

 - 57 )  . ( 67 - 34 ) - 67 . ( 34 - 57 )

= ( - 57 ) . 67 - ( - 57 ) . 34 - ( 67 . 34 - 67 . 57 )

= ( - 57 ) . 67 - ( - 57 ) . 34 - 67 . 34 + 67 . 57

= 67 . [ ( - 57 ) + 57 ] - 34 . ( 67 - 57 )

= 67 . 0 - 34 . 10

= 0 - 340

= 340