Question

TÍNH nhanh a ) ( - 25 ) × ( 75 - 45 ) - 75 × ( 45 - 25 ) 

 

Answer 1

( - 25 ) . ( 75 - 45 ) - 75 . ( 45 - 25 )

= ( - 25 ) . 75 - ( - 25 ) . 45 - 75 . 45 - ( - 75 ) . 25

= ( - 25 ) . 45 - 75 . 45

= [ ( - 25 ) + 75 ] . 45

= 50 . 45

= 2250

Answer 2

(-25) . (75 - 45) - 75 . ( 45 -25 )

= -25 . 75 - ( -25 ) . 45 - 75 . 45 - ( -75 ) . 25

= -25 . 75 + 25 . 45 - 75 . 45 + 75 . 25

= 75 . ( -25 + 25 ) +  45 . ( 25 - 75 )

= 75 . 0 + 45 . -50

= 0 +  ( -2250 )

=   -2250

Answer 3

(-25) . (75 - 45) - 75 . ( 45 -25 )

= -25 . 75 - ( -25 ) . 45 - 75 . 45 - ( -75 ) . 25

= -25 . 75 + 25 . 45 - 75 . 45 + 75 . 25

= 75 . ( -25 + 25 ) +  45 . ( 25 - 75 )

= 75 . 0 + 45 . -50

= 0 +  ( -2250 )

=   -2250