A)  AB x X = ABAB         => X = ABAB : AB = 101

B)   X x A = AA            => X = AA : A = 11

C)  ABC x X = ABCABC          => X =  ABCABC  : ABC = 1001 

D)  AB0AB0 : X = AB     => X = AB0AB0 : AB = 10010

                                  Các câu sau bạn tự làm nhé . Nhớ Tk cho mình nha Ok !

a, x * a = aa
    x = aa : a
    x = 11
b, ab * x = abab
    x = abab : ab
    x = 101
c, abc * x = abcabc
    x = abcabc : abc
    x = 1001
d, xx + x + 5 = 125
    x*(11 + 1) + 5 = 125 - 5
    x*12 = 120
    x = 120 : 12
    x = 10
e, xxx + xx + x + x = 992
    x*(111 + 11 + 1 + 1) = 992
    x*124 = 992
    x = 992 : 124
    x = 8
f, 4725 + xxx + xx + x = 54909
    x*(111+11+1) = 54909 - 4725
    x*123 = 50184
    x = 50184 : 123
    x = 408
g, xxx - xx -x - 25 = 4430
    x*(111-11-1) = 4430 + 25
    x*99 = 4455
    x = 4455 : 99
    x = 45
h, xxx + xx + x + x + x + 1 = 1001
  x*(111 + 11 + 1 + 1 + 1) = 1001 - 1
  x* 125 = 1000
  x = 1000 : 125
  x = 8 
Chúc bạn học tốt

A × x = aa

      X = aa ÷ a 

     X= 11

a,  \(\overline{xx}+x+5=125\)

      \(x\times11+x=120\)

      \(x\left(1+11\right)=120\)

      \(x=120\div12\)

      \(x=10\)

  Vậy x = 10

\(\overline{xxx}+\overline{xx}+x+x=992\)

\(x\times111+x\times11+x\times2=992\)

\(x\left(111+11+2\right)=992\)

 \(x=992\div124\)      

\(x=8\)

 Vậy x = 8

\(4725+\overline{xxx}+\overline{xx}+x=54909\)

\(x\times111+x\times11+x=50184\)

\(x\left(111+11+1\right)=50184\)

\(x\times123=50184\)

\(x=408\)

Vậy x = 408

b,  \(\overline{xxx}-\overline{xx}-x-25=4430\)

\(x\times111-x\times11-x=4455\)

\(x\left(111-11-1\right)=4455\)

\(x=4455\div99\)

\(x=45\)

Vậy x = 45

\(\overline{xxx}+\overline{xx}+x+x+x+1=1001\)

\(x\times111+x\times11+x\times3=1000\)

\(x\left(111+11+3\right)=1000\)

\(x=1000\div125\)

\(x=8\)

Vậy x = 8

\(35655-\overline{xxx}-\overline{xx}-x=5274\)

\(x\times111+x\times11+x=30381\)

\(x\left(111+11+1\right)=30381\)

\(x=30381\div123\)\

\(x=247\)

 Vậy \(x=247\)

\(xxx+xx+x+x=992\)

\(111x+11x+x+x=992\)

\(x\times\left(111+11+1+1\right)=992\)

\(x\times124=992\)

\(x=992\div124\)

\(x=8\)

\(4725+xxx+xx+x=54909\)

\(4725+111x+11x+x=54909\)

\(4725+x\times\left(111+11+1\right)=54909\)

\(4725+x\times123=54909\)

\(x\times123=54909-4725\)

\(x\times123=20184\)

Tự tính x

xx+x+5 =65 nha

xxxx-xx-x-25=4430

xxxx-xx-x    =4430-25(tim so hang)

Xx111-Xx11-x=4405

Xx(111+11+1)=4405

Xx1099=4405

x          =4405:1099(tim thua so)

x            =4(dư 9)

b) XXX + XX + X + X = 992

   X x 111 + X x 11 + X x 2 = 992

  X x (111 + 11 + 2) = 992

 X x 124 = 992

X = 992 : 124 = 8

8

xxx + xx + x + x = 992 

x * 111 + x * 11 + x + x = 992 

x* (111 + 11 + 1 + 1) = 992 

x* 124 = 992 

x = 992 : 124 

x = 8 

                                       xxx+xx+x+x=992

                x*111+x*11+x*1+x*1=992

                x *(111+11+1+1)=992

                                 x*124=992

                                        x=992:124

                                        x=8

xx + x + 5 = 25

x * 11 + x * 1 + 5 = 25

x * (11+1) + 5 = 125 

x * 12 = 120 

x = 120 : 12 

x = 10

xxx - xx - x - 25 = 4430 

x * 111 -x * 11 - x * 11 - 25 = 4430 

x * 99 - 25 = 4430

x * 99 = 4430 + 25 

x * 99 = 4455

x = 4455 : 9

x = 45

xxx + xx + x + x = 992 

x * 111 + x * 11 + x * 1 + x * 1= 992

x * ( 111 +11 +1+1) = 992

x * 124 = 992 

x = 992 : 124 

x = 8

mấy con khác cũng tương tự nhé .

đúng thì nhé

Ta có 

xx + x + 5 = 25

x * 11 + x * 1 + 5 = 25

x * (11+1) + 5 = 125 

x * 12 = 120 

x = 120 : 12 

x = 10

xxx - xx - x - 25 = 4430 

x * 111 -x * 11 - x * 11 - 25 = 4430 

x * 99 - 25 = 4430

x * 99 = 4430 + 25 

x * 99 = 4455

x = 4455 : 9

x = 45

xxx + xx + x + x = 992 

x * 111 + x * 11 + x * 1 + x * 1= 992

x * ( 111 +11 +1+1) = 992

x * 124 = 992 

x = 992 : 124 

x = 8

XX + X + 5 = 125

X x 11 + X x 1 + 5 = 125

X x (11 + 1) +5     = 125

X x 12 + 5 = 125

X x 12       = 125 - 5

X x 12       = 120

X              = 120 : 12

X = 10