(-4) + (-440) + (-6) + 440 = -4 - 440 - 6 + 440 = -10

(17 - 30) - (2015 + 17 - 30) = 17 - 30 - 2015 - 17 + 30 = 17 - 17 - 30 + 30 - 2015 = -2015

-50

- 3

= 5

5

13 + 21.5 - (198 : 11 - 8)

= 13 + 105 - 10

= 108

272 : 16 - 5 +4 (30 - 5 - 255 : 17)

= 17 - 5 + 4. ( 30 - 5 - 15 )

= 16 . 10

= 160

15.24 - 14.5 (145 : 5 - 27)

= 360 - 70 ( 29 - 27 )

= 290 . 2

= 580

18.3 - 18.2 + 3 (51 : 17)

= 54 - 36 + 3 . 3

= 54 - 36 + 9

= 27

(64 + 115 + 36) - 25.8

= 215 - 200 

= 15

15.8 - (17 - 30 + 83) - 144 : 6

= 120 - 70 - 24

= 26

250 : 50 - (46 - 75 + 54) : 5

= 5 - 25 : 5 

= 5 - 5

= 0

13 (17 - 95 + 83) : 5 - 18 : 9

= 13. 5 : 5 - 2

= 65 : 5 - 2

= 13 - 2

= 11

140 - 180(47 - 90 + 43) + 7

= 140 - 180 . 0 + 7

= 140 + 7

= 147

24 (15 + 30 + 85 - 120):10

= 24. 10 : 10 

= 240 : 10

= 24

27 + 73 - 30 : (25 -10)

= 27 + 73 - 30 : 15

= 27 + 73 - 2

= 98

18 - 4 (27 - 90 + 73) : 10

= 18 - 4. 10 : 10

= 18 - 40 : 10

= 18 - 4

= 14

Bài 2: Tính

140 - [ 25 : (4 mũ 2 - 11) + 4 ]

= 140 - [25 : (16 - 11) + 4 ]

= 140 - [ 25 : 5 + 4 ]

= 140 - [ 5 + 4]

= 140 - 9 

= 131

a,(-17)+5+8+17=[(-17)+17]+5+8=0+13=13

b. 30+12+(-20)+(-12)=[12+(-12)]+30+(-20)=0+10=10

Nho k minh nha

a, (-17) + 5 + 8 + 17

   = -12 + 8 + 17

   = -4 + 17

   = 17 - 4

   = 13

b, 30 + 12 + (-20) + (-12)

   = 42 + (-20) + (-12) 

   = 42 - 20 - 12

   = (42 - 12) - 20

   = 30 - 20

   = 10

a: \(17\cdot85+15\cdot17-120\)

\(=17\left(85+15\right)-120\)

=1700-120

=1580

b: \(2^3\cdot17-2^3\cdot14\)

\(=2^3\left(17-14\right)\)

\(=8\cdot3=24\)

c: \(20-\left\lbrack30-\frac{\left(5-1\right)^2}{2}\right\rbrack\)

\(=20-30+\frac{4^2}{2}\)

\(=-10+\frac{16}{2}=-10+8=-2\)

d: \(80-\left(4\cdot5^2-3\cdot2^2\right)\)

\(=80-\left(4\cdot25-3\cdot4\right)\)

=80-100+12

=92-100

=-8

e: \(27\cdot77+24\cdot27-27\)

\(=27\left(77+24-1\right)\)

\(=27\cdot100=2700\)

f: \(174:\left\lbrace2\cdot\left\lbrack36+\left(4^2-23\right)\right\rbrack\right\rbrace\)

\(=\frac{174}{2\cdot\left(36+16-23\right)}=\frac{87}{52-23}=\frac{87}{29}=3\)

Chọn D

Oki, thank you bạn nhiều

\(\left(\frac{17}{28}+18.29+\frac{19}{30}+\frac{30}{31}\right).\left(\frac{-5}{12}+\frac{1}{4}+\frac{1}{6}\right)\)

\(=\left(\frac{17}{28}+18.29+\frac{19}{30}+\frac{30}{31}\right).\left(\frac{-5}{12}+\frac{3}{12}+\frac{2}{12}\right)\)

\(=\left(\frac{17}{28}+18.29+\frac{19}{30}+\frac{30}{31}\right).\left(\frac{-2}{12}+\frac{2}{12}\right)\)

\(=\left(\frac{17}{28}+18.29+\frac{19}{30}+\frac{30}{31}\right).0\)

\(=0\)

a) 2 + (-25) + 41+ (-2) + 25 +(-41)

= (-2 + 2) + (-25 + 25) + (-41 +41)

=0 + 0 + 0

=0

b) 10+ ( -17) +5 + (-7)+ 17 + (-15)

= (-15+10+5) + (-17+7) + 7

= 0 + 0 + 7

= 7

c)(-22) + (-14) + 17 + (-24) + 13+ 30

= [(-22) + (-14) + (-24)] + (17 + 13 + 30)

=-60 + 60

=0

a) 2 + (-25) + 41+ (-2) + 25 +(-41)

= (-2 + 2) + (-25 + 25) + (-41 +41)

=0 + 0 + 0

=0

=(576−577)+(678−679)+(780−475)=−1−1+305=303

??