Question

tính nhanh:

a) 85.(35-27) - 35.(85-27) =

b) 47.(45-15) - 47.(45+15) =

Answer 1

a)85.(35-27)-35.(85-27)

=85.35-27-35.85-27

=(85-85).(35-35).(27-27)

=0.0.0

=0

b)47.(45-15)-47.(45+15)

=47.45-15-47.45+15

=(47-47).(45-45).(15+15)

=0.0.30

=0

Answer 2

a) - 1350

b) - 141o

Answer 3

a) 85 . ( 35 - 27 ) - 35 . ( 85 - 27 )

= 85 . 35 - 85 . 27 - 35 . 85 + 35 . 27

= ( 85 . 35 - 35 . 85 ) - 27 . ( 85 - 35 )

= 0 - 27 . 50

= 0 - 1350

= -1350

b) 47 . ( 45 - 15 ) - 47 . ( 45 + 15 )

= 47 . ( 45 - 15 - 45 - 15 )

= 47 . (-30)

= -1410

Học tốt !!!

=))

Answer 4

a) 85 . ( 35 - 27 ) - 35 . ( 85 - 27 )

=  85 . 35 - 85 . 27 - 35 . 85 - 35 . 27

=  ( 85. 35 - 35 . 85 ) - 27 . ( 85 - 35 )

=  0 - 27 . 50

=  0 - 1350

=  -1350

Vậy : 85.(35-27) - 35.(85-27) = -1350

b) 47 . ( 45 - 15 ) - 47 . ( 45 + 15 )

=  47 . ( 45 - 15 - 45 - 15 )

=  47 . ( - 30 )

=  -1410

Vậy : 47.(45-15) - 47.(45+15) = -1410