Lời giải:

$=3965-2378-2378-437+1378-528$

$=3965-(2378-1378)-2378-437-528$

$=3965-1000-2378-437-528$

$=2965-(2378+437+528)=2965-3343=-378$

a) ( 1267-196 ) - ( 267 + 304 )

= ( 1267 - 267 ) - ( 196 + 304 )

= 1000 - 400

= 600

b ) ( 3965 - 2378 ) - ( 437-1378 ) - 528

=

a, (1267-196)-(267+304)

=(1267-267)-(196+304)

=1000-500

=500

b; (3965-2378)-(437-1378)-528

=(3965-528-437)-(2378-1378)

=3000-1000

=2000

(3965-2378)-(437-1378)-528

=1587-(-941)-528

=1587+941-528

=2528-528

=2000

=2000 nha

HT

a) 215+(-38)-(-58)+9-85

=215-38+58+9-85

=(215-38)+(58+9)-85

=177+67-85

=159

b)(1267-196)-(267-304)

=1071-(-37)

=1108

c)(3965-2378)-(437-1378)-528

=1578-(-941)-528

=2000.

Con d mk chiu.

a) 215 + (-38) - (-58) + 9-85

=215 - 38 + 58 + 9 - 85

=(215 - 38) + (58 + 9) - 85

=177 + 67 - 85

=159

b)(1267 - 196) - (267 - 304)

=1071 - (-37)

=1108

c)(3965 - 2378) - (437 - 1378) - 528

=1578 - (-941) - 528

=2000

chụp lại , nét hơn nha

    (1267 - 196) - (267 - 204)

=  1267 - 196 - 267 + 204

= (1267 - 267)  + (204 - 196)

= 1000 + 8

= 1008

   (3965 - 2378) - (437 - 1378) - 528

= 3965 - 2378 - 437 + 1378 - 528

= 3965  - (437 + 528) - (2378 - 1378)

= 3965 - 965 - 1000

= 3000 - 1000

= 2000

    2002 - 79 + 15 - (-79) - 15 

= 2002  - (79 - 79)  + (15 - 15)

= 2002 - 0 + 0

= 2002

    -329 - (15 - 101) - (25 - 440)

= - 329 - 15 + 101 - 25 + 440

= (440 + 101 - 329) - (15 + 25)

= (541 - 329) - 40

= 212 - 40

= 172

a) (871 - 28 ) + ( 229 - 72 )

= 871 - 28 + 229 - 72

= (871 + 229) - (28 + 72)

= 1100 + 100 = 1200

b) ( 689 - 31 ) - ( 269 - 111 )

= 689 - 31 - 269 + 111

= (689 + 111) - (31 + 269)

= 800 - 300= 500

c) 215 + ( - 38) - ( - 58) + 90 - 85

= 215 - 38 + 58 + 90 - 85

= (215 - 85) + (58 - 38) + 90

= 130 + 20 + 90 = 240

d) 31 - [ 26 - ( 209 + 35 ) ]

= 31 - 26 + 209 + 35

= (31 + 209) + (35 - 26)

= 240 + 9 = 249

e) ( 1267 - 196 ) - ( 267 + 304 ) 

= 1267 - 196 - 67 - 304

= (1267 - 67) - (196 + 304)

= 1200 - 500 = 700

f) ( 3965 - 2378 ) - ( 437 - 1378 ) - 528

= 3965 - 2378 - 437 + 1378 - 528

= 3965 - (2378 - 1378) - (437 + 528)

= 3965 - 1000 - 965 = 3000 - 1000 = 2000

Chúc em học tốt!!!

a) 

871+299- (72+28)

= 1710 - 100

= 1070

k nhé

b) 

=689- 111- (269+31)

= 578 - 300

= 278

k nhoa

a: \(\left(3965-2378\right)-\left(437-1378\right)-528\)

\(=3965-2378-437+1378-528\)

\(=\left(3965-437-528\right)-\left(2378-1378\right)\)

\(=3000-1000=2000\)

b: \(\left(-457\right)+\left(-123\right)+23+237\)

\(=\left(-457+237\right)+\left(-123+23\right)\)

\(=-220-100=-320\)

c: \(\left(-329\right)-\left(15-101\right)-\left(25-440\right)\)

\(=-329-15+101-25+440\)

\(=\left(440-15-25\right)+\left(-329+101\right)\)

\(=400-228=172\)