Giải thích các bước giải:
a, ( 3567 - 214 ) - 3567
= 3567 - 214 - 3567
= ( 3567 - 3567 ) - 214
= 0 - 214
= - 214
b, ( - 2017 ) - ( 28 - 2017 )
= - 2017 - 28 + 2017
= [(-2017) + 2017] - 28
= 0 - 28
= - 28
c, - ( 269 - 357 ) + ( 269 - 357 )
= - 269 + 357 + 269 - 357
= [( - 269 ) + 269] + ( 357 - 357 )
= 0
d, ( 123 + 345 ) + ( 456 - 123 ) - [2017 - ( - 345)]
= 123 + 345 + 456 - 123 - 2017 - 345
= ( 123 - 123 ) + ( 345 - 345) + 456 - 2017
= 0 + 456 - 2017
= - 1561
