(18+29) +( 158 -18-29)
= 18 + 29 + 158 - 18 - 29
= 18 - 18 + 29 - 29 + 158
= 0 + 0 + 158
= 158
(13-135+49)-(13+49)
= 13 - 135 + 49 - 13 - 49
= 13 - 13 + 49 - 49 - 135
= 0 + 0 -135
= -135
( 18 + 29 ) + ( 158 - 18 - 29 )
= 18 + 29 + 158 - 18 - 29
= ( 18 - 18 ) + ( 29 - 29 ) + 158
= 0 + 0 + 158
= 158
( 13 - 135 + 49 ) - ( 13 + 49 )
= 13 - 135 + 49 - 13 - 49
= ( 13 - 13 ) + ( 49 - 49 ) - 135
= 0 + 0 - 135
= -135
( 18 + 29 ) + ( 158 - 18 - 28 )
= 18 + 29 + 158 - 18 - 29
= [18 + ( -18 ) ] + [ 29 - 29 ] + 158
= 0 + 0 + 158
= 158
Câu cuối cùng bn tự làm nha!
(18 + 29) + (158 - 18 - 29)
= 18 + 29 + 158 - 18 - 29
= (18 - 18) + (29 - 29) + 158
= 0 + 0 + 158
= 158
(13 - 135 + 49) - (13 + 49)
= 13 - 135 + 49 - 13 - 49
= (13 - 13) + (49 - 49) - 135
= 0 + 0 - 135
= -135
(18 + 29) + (158 - 18 - 29)
= 18 + 29 + 158 - 18 - 29
= (18 - 18) + (29 - 29) + 158
= 0 + 0 + 158
= 158
