a)

\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{47}\\{35}\end{array}}\\\hline{\,\,\,\,82}\end{array}\)                                    \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{82}\\{47}\end{array}}\\\hline{\,\,\,35}\end{array}\)

\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{526}\\{147}\end{array}}\\\hline{\,\,\,\,673}\end{array}\)                                \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{673}\\{147}\end{array}}\\\hline{\,\,\,526}\end{array}\)

b) 350 + 42 – 105 = 392 – 105 = 287

     1 000 – 300 + 77 = 700 + 77 = 777.

\(\Rightarrow\left(x-1\right)\in BC\left(52;35\right)=\left\{1820;3640;5460;...\right\}\)

\(\Rightarrow x\in\left\{1821;3641;5461;...\right\}\)

Mà \(1000< x< 2000\)

\(\Rightarrow x=1821\)

\(3,8=3\frac{8}{10};7,54=7\frac{54}{100};16,35=16\frac{35}{100};35,576=35\frac{576}{1000}\)

\(\frac{73}{10}=7\frac{3}{10}=7,3;\frac{86}{100}=0,86;\frac{5375}{1000}=5\frac{375}{1000}=5,375;\frac{673}{1000}=0,673;\frac{9356}{10000}=0,9356\)

lm ko ai tick nên thôi 

\(128673-x=5050:5\\ 128673-x=1010\\ x=128673-1010\\ x=127663\)

128673-x=5050:5=1010

=>x=128673-1010=127663.

128 637 - x = 1010

x = 128 637 - 1010

x = 127 627

a. X + 673 = 768

         X      = 768 – 673 

         X      = 95 

b. X : 7 = 427

    X      = 427 x 7

    X      = 2989

Hô nhiều nhưng cố lên các bn ơi các bn sẽ làm được mà

Bạn ghi rõ dấu nhân với x ra , mk chẳng phân biệt đc

(X:10)+37=60<=>X:10=23=>X=230

25xX-15xX=72<=>10xX=72=>X=7,2

138-(Xx5)=38<=>Xx5=100=>X=20

(Xx9):52=18<=>Xx9:52=18=>x:52=2=>x=104

52xX+48xX=100=>100xX=100=>X=1

623xX-123xX=1000=>500xX=100=>X=2

Xx16+84xX=700=>100xX=700=>X=7

236xX-Xx36=2000=>200xX=2000=>X=10

216:X+34:X=10=>250:X=10=>X=25

2125:X-125:X=100=>2000:X=100=>X=20

Đáp án B