b: =124-312+76-112+21

=200-424+21

=221-424

=-203

a: =735+23-135+177=600+200=800

b: =124-312+76-112+21=200-424+21=-203

c: =183+21+65-183-21=65

d: \(=-271+37-160+31-137=-500\)

e: =-3a+b-3c+b+3c+2a-2b

=-a

Đáp án đúng: A. 85 732

=300

=200

=-4 

Ra đề sáng tạo đó

e)371+731-271-531

=(371-271)+(731-531)

=100+200

=300

e) = (371-271)+(731-531)

= 100 + 200 = 300

f) (57 - 17)+(58-18)+(59-19)+(60-20)+(61-21)

= 40+40+40+40+40 = 200

g) (9-10)+(11-12)+(13-14)+(15-16)

= -1+(-1)+(-1)+(-1)

= -4

giai ho mik voi

a) 22 + ( - 47 ) + ( - 153 ) + 8

= ( 22 + 8 ) - ( 47 + 153 )

= 30 - 200

= - 170

b) 9 + ( - 10 ) + 11 + ( - 12 ) + 13 + ( - 14 ) + 15 + ( - 16 )

= ( 9 - 10 ) + ( 11 - 12 ) + ( 13 - 14 ) + ( 15 - 16 )

= - 1 - 1 - 1 - 1

= - 4

c) 371 + ( - 271 ) + ( - 531 )

= ( 371 - 271 ) - 531

= 100 - 531

= - 431

d) ( - 18 ) - 54 + ( - 46 ) - 62

= ( - 18 - 62 ) - ( 54 + 46 )

= 80 - 100

= - 20

\(a,2\times31\times12+4\times6\times42+8\times27\times3\)

\(=24\times31+24\times42+24\times27\)

\(=24\times\left(31+42+27\right)\)

\(=24\times100\)

\(=2400\)

\(b,583.931+69.\left(170+583\right)+31.170\)

\(=583.931+69.170+69.583+31.170\)

\(=583.\left(931+69\right)+170.\left(69+31\right)\)

\(=583.1000+170.100\)

\(=583000+17000\)

\(=600000\)

\(c,732.976+24.\left(680+732\right)+76.680\)

\(=732.976+24.680+24.732+76.680\)

\(=732.\left(976+24\right)+680.\left(24+76\right)\)

\(=732.1000+680.100\)

\(=732000+68000\)

\(=800000\)

Học tốt

a)2400

b)600000

c)800000

a) 2 x 31 x 12 + 4 x 6 x 42 + 8 x 27 x 3

= 24 x 31 + 24 x 42 + 24 x 27

= 24 x ( 31 + 42 + 27 )

= 24 x 100

= 2400

b) 583 x 931 + 69 x ( 170 + 583 ) + 31 x 170

= 583 x 931 + 69 x 170 + 69 x 583 + 31 x 170

= 583 x ( 931 + 69 ) + 170 x ( 69 + 31 )

= 583 x 1000 + 170 x 100

= 583000 + 17000

= 600000

c) 732 x 976 + 24 x ( 680 + 732 ) + 76 x 680

= 732 x 976 + 24 x 680 + 24 x 732 + 76 x 680

= 732 x ( 976 + 24 ) + 680 x ( 24 + 76 )

= 732 x 1000 + 680 x 100

= 732000 + 68000

= 800000

a, 879 + [ 64 + (-879) + 36 ]

= 879 + 64 - 879 + 36

= (879 - 879) + (64 + 36)

= 100

b, -564 + [ (-724) + 564 + 224 ]

= - 564 - 724 + 564 + 224

= (-564 + 564) + (-724 + 224)

= 0 - 500

= 500

c, [ 461 + (-78) + 40 ] + (-461)

= 461 - 78 + 40 - 461

= (461 - 461) + (40 - 78)

= -38

d, [ 53 + (-76) ] - [ -76 - (-53) ]

= 53 - 76 + 76 - 53

= (53 - 53) + (-76 + 76)

= 0

e, 371 + 731 - 271 - 531

= (371 - 271) + (731 - 531)

= 100 + 200

= 300

f, 57+59+60+61-17-18-19-20-21

= (57 - 17) + (59 - 19) + (60 -20) + (61 - 21) - 18

= 40 + 40 + 40 + 40 -18

= 40 *4 - 18

= 160 - 18

= 142

g, 9-10 + 11-12 + 13-14 + 15-16

= (9-10) + (11-12) + (13-14) + (15-16)

= -1 + (-1) + (-1) + (-1)

= -1 * 4

= -4

h, -1-2-3-4-5 ... -1999-2000-2001-2002

i, [ 453 + 64 + (-879) ] + (-517)

= 453 + 64 - 879 - 517

= [(453 + 64) - 517] - 879

= 0 - 879

= -879

j, -323 + [ (-874) + 564 - 241 ]

= -323 - 874 + 564 - 241

= [(-323 - 241) + 564] - 874

= 0 -874

= -874

a: =371-271-531+731=100+200=300

b: =-321-28-327+27

=-350-300

=650

c: =-424-371+424+29=-342

d: =-249+248=-1

a)371+(-271)+(-531)+731=300

b)-312+(-327+(-28)+27=650

c)-424+(-371)-(-424)-(-29)=-342

d)-249+197+248+(-197)=-1

e)3+(-5)+(-9)+11+(-13)=-13

g)-8+10+(-12)+14+(-16)+18=6