ta có
3579-(49-5+3579)+49
=3579-49+5-3579+49
=5
3579 - ( 49 - 5 + 3579 ) + 49
= 3579 - 49 + 5 - 3579 + 49
= ( 3579 - 3579 ) + ( 49 - 49 ) + 5
= 0 + 0 + 5
= 5
3579 - [49 - 5 + 3579] + 49
= 3579 - 49 + 5 - 3579 +49
= 5
3579 - [44 + 3579]+ 49
= 3579 - 3623 +49
= (-44) + 49
=5
3579 - [49-5+3579]+49
=[3579-3579]-[49-49]+5
=0+0+5
=5