10 - [ ( 9 . 7 + 21 ) : 2 + 8 ]
= 10 - [ 84 : 2 + 8 ]
= 10 - 50
= 50
= 10 - [(21 + 21): 2 + 8]
= 10 - [42 : 2 + 8 ]
= 10 - [ 21 + 8 ]
= 10 - 29
= (-19)
10 - [ ( 9 . 7 + 21 ) : 2 + 8 ]
= 10 - [ ( 63 + 21 ) : 2 + 8 ]
= 10 - [ 84 : 2 + 8 ]
= 10 - [ 42 + 8 ]
= 10 - 50
= - ... tự tính
10-[ ( 9.7+21):2+8]
=10-[(63+21):2+8]
=10-( 84 :2+8)
=10-( 42+8)
=10-50
=-40