Bài 2: Bỏ dấu ngoặc rồi tính. a)(123 – 27) + (27 + 13 – 123) b)(175 + 25 + 13) – (-15 + 175 + 25) c)(2012 – 119 + 29) – (-119 + 29) d)– (55 – 80 + 91) – (2012 + 80 – 91) e)(56-27)-(11+28-16) f)214-(-36)+(-305) Bài 3: Tính a.(-10)-21-18 b.24 – (-16)+(-15) c.49- [15+(-6)] d.(-44)-[(-14)-30] e.125 – (115-99) f.21-22+23-24 gõ câu trả lời ko ghi ra vở nếu ghi ra vở em vote 2 sao thôi

bài 2:

`a) (123-27) + (27+13-123)`

`= 123-27+27+13-123`

`= 13`

`b) (175+25+13) - (-15+175+25)`

`= 175+25+13+15-175-25`

`= 13+15=28`

`c) (2012-119+29) - (-119+29)`

`= 2012-119+29+119-29`

`= 2012`

`d) - (55-80+91) - (2012+80-91)`

`= -55+80-91-2012-80+91`

`= -55-2012`

`= -2067`

`e) (56-27) - (11+28-16)`

`= 56-27-11-28+16`

`= 6`

`f) 214 - (-36) + (-305) `

`=214+36-305`

`= -55`

Bài 3: 

`a. (-10)-21-18`

`= -10-21-18`

`= -49`

`b. 24 - (-16)+(-15) `

`= 24+16-15`

`=25`

`c. 49- [15+(-6)]`

`= 49- (15-6)`

`= 49-9`

`=40`

`d. (-44) - [(-14)-30]`

`= -44 + (14-30)`

`= -44 + (-16)`

`= -44-16`

`= -60`

`e. 125- (115-99)`

`=125-115+99`

`=109`

`f. 21-22+23-24`

`= -1+(-1)`

`= -1-1`

`= -2`