123 + 1234 - 123 + 1234 - 1 + 2 = 2469

230 + 672 - 721 = 181

123+123-123-1234-1+2=1

230+672-721=181

T.I.C.K cho mình nha

sorry câu 1 mình nhần  phải là 2469

a. 164 x 123 = 20172

b. 672 : 21 = 32

`123xx77+123xx23`

`=123xx(77+23)`

`=123xx100`

`=12300`

123 + x = 123 + 77

=> x = 77

123 + x = 123 + 77

123 + x = 200

          x = 200 - 123

          x = 77

123 + x = 123 + 77

123 + x = 200

          x = 200 - 123

          x = 77

a: -23-12=-(23+12)=-35

a: -100-12=-(100+12)=-112

a: -123-20=-(123+20)=-143

a: 43-(-53)=43+53=96

a: 14-(-20)=14+20=34

a: -15-(-17)=-15+17=17-15=2

a: 143-(-123)=143+123=266

b: 12-(5-7)=12-(-2)=12+2=14

b: 15-(-9)-4=11+9=20

b: -17-(8-25)=-17-8+25=-25+25=0

b: -5+10-12-5=(10-5-5)-12=0-12=-12

b: (1456+23)-1456=1456-1456+23=0+23=23

b: (2354-45)-2354=2354-45-2354=-45

b: -2021-(57-2021)=-2021-57+2021=-57

c: 283+581-282-531=(283-282)+(581-531)=50+1=51

c: 3758+57-3769-66

=(3758-3769)+(57-66)

=(-11)+(-9)

=-(11+9)

=-20

c: 2575+37-2575+29

=37+29

=66

c: 17+33+(-37)+(-33)

=(17-37)+(33-33)

=0+(-20)

=-20

c: -4+(-10)+25+(-11)

=(-4-10-11)+25

=25-25

=0

c: 42-69+17+(-42)-17

=(42-42)+(17-17)+(-69)

=-69

c: (-2)+(-370)+(-8)+370

=(-2-8)+(-370+370)

=-10+0

=-10

A=123^2 + 54.123 + 77^2 
= 123^2 + 2.123.77 + 77^2 - (154-54).123 
= (123+77)^2 - 100.123 
= 200^2 -12300 
= 40000-12300 
= 27700.

34226 OK

34226 nha

459.123

310

a) \(123+345+57\times2=123+345+114=468+114=582\)

b) \(123+77+55+55=\left(123+77\right)+\left(55+55\right)=200+110=310\)

a)459,123

b)310