Phá ngoặc được
25+51+42-25-53-51
=42-53
=-11
hok tốt
( 25 + 51) + ( 42 - 25 -53 -51 )
= 76 + ( - 87 )
= - 11
(25+51)+(42-25-53-51)
=(25-25)+(51-51)+(53-42)
= 0 + 0 +11
= 11
( 25 + 51 ) + ( 42 - 25 - 53 - 51 )
= 25 + 51 + 42 - 25 - 53 - 51
= ( 51 - 51 ) + ( 25 - 25 ) + ( 42 - 53 )
= 0 + 0 + (-11)
= -11
(25+51)+(42-25-53-51)
=76+(-87)
=-(87-76)=-11