Question

Tính nhanh: 42 . ( 52 - 17 ) - 52 . ( 42 - 17 )
Cám ơn mọi người!

Answer 1

42.(52 - 17) - 52.(42 - 17)

= 42.35 - 52 . 25

= 42.25 . 1,4 - 52.25

= 58,8 . 25 - 52.25

= (58,8 - 52) .25

= 6,8 .25

= 170

k mik nha

Answer 2

42 . ( 52 - 17 ) - 52 . ( 42 - 17 )

= 42 . 52 - 42 . 17 - 52 . 42 - 52 . 17

= [( 42 . 52 ) . 42 - 52 ] - [( - 42 . 17 ) . 42 . 17 ]

= 0 - 0 

= 0

Answer 3

42.(52-17)-52.(42-17)

=42.52-42.17-52.42+52.17

=-42.17+52.17

=17.(-42+52)

=17.10

=170