a.980099

B.979999

B:ĐÚNG

A:SAI

3478 < 34 780 99 999 < 100 000 43 980 > 37 980

82 879 > 82 789 56 812 > 55 812 34 567 = 34 567.

3478 < 34 780    99 999 < 100 000    43 980 >37 980

82 879 > 82 789    56 812 >55 812    34 567 = 34 567

x + 630 = 630 + 1000

x + 630 = 1630

x          = 1630 - 630

x          = 1000

x + 630 = 630 + 1000

x + 630 = 1630

x          = 1630 - 630

x          = 1000

x + 630 = 630 + 1000

x + 630 = 1630

x = 1630 - 630

x = 1000

Mk nhanh nhất đó

**** mk nha 

x + 630 = 250 + 630

x + 630 = 880

x = 880-630

x = 250

x + 630 = 250 + 630

=> x + 630 =880

=> x = 880 - 630 

=> x = 250

x=250

\(-\left(-630\right)+915+\left(-630\right)+\left(-615\right)\)

\(=630+915-630-615\)

\(=915-615\)

\(=300\)

 -(-630)+915+(-630)+(-615)

= 630 + 915 - 630 - 615

= (630 - 630) + (915 - 615)

= 0 + 300

= 300

\(-\left(-630\right)+915+\left(-630\right)+\left(-615\right)\)

\(=630+915-630-615\)

\(=\left(630-630\right)+\left(915-615\right)\)

\(=0+300\)

\(=300\)

11/92

19/245

9/7558

17/196

86/879

\(11\) \(\div\) \(92\) \(=\) \(\frac{11}{92}\)

\(76\) \(\div\) \(980\) \(=\) \(\frac{76}{980}\) \(=\) \(\frac{19}{245}\)

\(9\) \(\div\) \(7558\) \(=\) \(\frac{9}{7558}\)

\(85\) \(\div\) \(980\) \(=\) \(\frac{85}{980}\) \(=\) \(\frac{17}{196}\)

\(86\) \(\div\) \(879\) \(=\) \(\frac{86}{879}\)

11:92=\(\frac{11}{92}\)

76:980=\(\frac{19}{245}\)

9:97558=\(\frac{9}{7558}\)

85:980=\(\frac{17}{196}\)

86:879=\(\frac{86}{879}\)

5686*980 = 5572280

5686 x 980 =5 572 280

ủng hộ mk nha

5686*980=5572280

nhannh

900:x = 1030

=> x = 900/1030

=> x= 90/103

\(\dfrac{9}{13}\)

\(900+x-50=980\\ x-50=980-900\\ x-5=80\\ x=80+50\\ =130.\)

900+x-50=980

900+x=980+50

900+x=1030

x=1030-900

x=130

900 + x = 980 + 50

900 + x =   1030

          x  = 1030 - 900

          x =    130

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