-57 . ( 67 - 34) - 67 . ( 34 - 57)
= -57 . 67 - (-57) . 34 - 67 . 34 - 67 . 57
= - 57 . 67 + 57 . 34 - 67 . 34 - 67 . 57
= - ( 57 . 67 - 67 . 57 ) + 34 . (57-67)
= 0 + 34 . (-10)
= 34 . (-10)
= -340
c) -98 . (1-246) - 246
= -98 . 1 - (- 98 ) . 246 - 246
= - 98 + 98 . 246 - 246
= - 98 + 98 . (246-246)
= -98 + 98 . 0
= -98 + 0
= -98
@skymeo gửi bn ạ . Chúc bn hc tốt!!
