Giúp em với ạ mai em phải nộp rồi

a)`[461+(-78)+40]+(-461)=461-78+40-461`

`=(461-461)-(78-40)=0-38=-38`

`--------`

`b)[53+(-76)]-[-76-(-53)]=53-76+76-53`

`=(53-53)-(76-76)=0-0=0`

`--------`

`c)-564+[(-724)+564+224]=-564-724+564+224`

`=(-564+564)-(724-224)=0-500=-500`

`--------`

`d)-87+(-12)-(-487)+512=-87-12+487+512`

`=(-87+487)+(-12+512)==400+500=900`

`--------`

`e)942-2567+2563-1942=-(1942-942)+(2563-2567)`

`=-1000+(-4)=-1004`

`--------`

`f)1152-(374+1152)+(-65+374)`

`=1152-374-1152-65+374`

`=(1152-1152-(374-374)-65=-65`