Bài 2. Bỏ dấu ngoặc rồi tính
a, -7264 + (1543 + 7264)
g, (36 + 79) + (145 – 79 – 36)
b, (144 – 97) – 144
h, 10 – [12 – (- 9 – 1)]
c, (-145) – (18 – 145)
i, (38 – 29 + 43) – (43 + 38)
d, 111 + (-11 + 27)
k, 271 – [(-43) + 271 – (-17)]
e, (27 + 514) – (486 – 73)
m, -144 – [29 – (+144) – (+144)]
Đáp án:
a, -7264 + (1543 + 7264 ) g, ( 36 + 79 ) + ( 145 – 79 – 36 )
= -7264 + 1543 + 7264 = 36 + 79 + 145 – 79 – 36
= ( -7264 + 7264 ) + 1543 = ( 36 – 36 ) + ( 79 – 79 ) + 145
= 0 + 1543 = 0 + 0 + 145
= 1543 = 145
b, ( 144 – 97 ) – 144 h, 10 – [ 12 – ( -9 – 1 )]
= 144 – 97 – 144 = 10 – [12 – (-10 )]
= ( 144 – 144 ) – 97 = 10 + 2
= 0 – 97 =12
= -97
c, ( -145 ) – ( 18 – 145 ) i, (38 – 29 + 43) – (43 + 38)
= ( -145 ) – 18 + 145 = 38 – 29 + 43 – 43 – 38
= [( -145 ) + 145 ] – 18 = ( 38 – 38) + ( 43 – 43 ) – 29
= 0 – 18 = 0 + 0 – 29
= -18 = -29
d, 111 + ( -11 + 27 ) k , 271 – [(-43) + 271 – (-17 )]
= 111 + ( -11 ) + 27 = 217 – ( -43 ) – 271 + ( -17 )
= 100 + 27 = [ 217 + ( -17 )] – [( -43 ) – 271]
= 127 = 200 – ( -314 )
= 514
e,(27 + 514) – (486 – 73) m, -144 – [29 – (+144 ) – (+144)]
= 27 + 514 – 486 + 73 = -144 – 29 + 144 + 144
= ( 27 + 73 ) + ( 514 – 486 ) = (-144 + 144 )-(29 + 144 )
= 100 + 28 = 0 – 173
= 128 = -173
haizz , mệt quá , xin hay nhất nhé !
Đáp án:
Giải thích các bước giải:
`a) -7264+ (1543+ 7264)`
`= -7264+ 1543+ 7264`
`= -7264+ 7264+ 1543`
`= 0+ 1543`
`= 1543`
`g) (36+ 79)+ (145- 79- 36)`
`= 36+ 79+ 145- 79- 36`
`= (36- 36)+ (79- 79)+ 145`
`= 0+ 0+ 145`
`= 145`
`b) (144- 97)- 144`
`= 144- 97- 144`
`= (144- `44)- 97`
`= 0- 97`
`= -97`
`h) 10- [12- (-9- 1) ]`
`= 10- [12+ 9+ 1]`
`= 10- [12+ 10]`
`= 10- 12- 10`
`= (10- 10)- 12`
`= 0- 12`
`= -12`
`c) (-145)- (18- 145)`
`= (-145)- 18+ 145`
`= [(-145)+ 145]- 18`
`= 0- 18`
`= -18`
`i) (38- 29+ 43)- (43+ 38)`
`= 38- 29+ 43- 43- 38`
`= (38- 38)+ (43- 43)- 29`
`= 0+ 0- 29`
`= -29`
`d) 111+ (-11+ 27)`
`= 111+ (-11)+ 27`
`= [111+ (-11)]+ 27`
`= 100+ 27`
`= 127`
`k) 271- [(-43)+ 271- (-17)]`
`= 271- [(-43)+ 271+ 17]`
`= 271+ 43- 271- 17`
`= (271- 271)+ (43- 17)`
`= 0+ 26`
`= 26`
`e) (27+ 514)- (486- 73)`
`= 27+ 514- 486+ 73`
`= (27+ 73)+ (514- 486)`
`= 100+ 28`
`= 128`
`m) -144- [29- (+144)- (+144)]`
`= -144- [29- 144- 144]`
`= -144- 29+ 144+ 144`
`= (-114+ 114)+ (-29+ 144)`
`= 0+ 115`
`= 115`