a) 185 + 434 + 515 + 266 + 155
= ( 185 + 515 + 155 ) + ( 434 + 266 )
= 855 + 700
= 1555
b) 12 . 53 + 53 . 17 - 53 . 84
= 53 . ( 12 + 17 - 84 )
= 53 . ( - 55 )
= -2915
a, 185 + 434 + 515 + 266 + 155
= ( 185 + 515 + 155 ) + ( 434 + 266 )
= 855 + 700
= 1555
b, 12 . 53 + 53 . 17 - 53 . 84
= 53 . ( 12 + 17 - 84 )
= 53 . ( -55 )
= -2915
c, 19 . 128 + 36 . 82 + 64 . 69 + 64 .41
= 2432 + 2952 + 64 . ( 69 + 41 )
= 5384 + 64 . 110
= 5384 + 7040
= 12424
a)185+434+515+266+155
=(185+515)+(434+266)+155
=700+700+155
=1400+155
=1555
b)12x53+53x17-53x84
=53x(12+17-84)
=53x(-55)
=(-2915)
c)19x128+36x82+64x69+64x41
=19x128+36x82+64x(69+41)
=2432+2952+6400
=11784
Tính hợp lí :
a, 185 + 434 + 515 + 266 + 155
= ( 185 + 515 + 155 ) + ( 434 + 266 )
= 855 + 700
= 1555
b,12 . 53 + 53 . 17 - 53 . 84
= 53 . ( 12 + 17 - 84 )
= 53 . ( -55 )
= - 2915
c, 19 . 128 + 36 . 82 + 64 . 69 + 64 . 41
= 19 . 128 + 36 . 82 + 64 . ( 69 + 41 )
= 19 . 128 + 36 . 82 + 64 . 110
= 2432 + 2952 + 7040
= 5384 + 7040
= 12 424
Sorry nha mk sai con c
c)19x128+36x82+64x69+64x41
=2432+2952+7040
=12424
a, 185 + 434 + 515 + 266 + 155
= ( 185 + 515 + 155 ) + ( 434 + 266 )
= 855 + 700
= 1555
b,12 . 53 + 53 . 17 - 53 . 84
= 53 . ( 12 + 17 - 84 )
= 53 . ( -55 )
= - 2915
c, 19 . 128 + 36 . 82 + 64 . 69 + 64 . 41
= 19 . 128 + 36 . 82 + 64 . ( 69 + 41 )
= 19 . 128 + 36 . 82 + 64 . 110
= 2432 + 2952 + 7040
= 5384 + 7040
= 12 424
