\(5\frac{4}{7}\): [ x : 1,3 + 8,4 . \(\frac{6}{7}\). ( 6 - \(\frac{\left(2,3+5\div6,25\right)\times7}{8\times0,-125+6,9}\)) ] = \(1\frac{1}{14}\)

\(\frac{39}{7}\): [ x : 1,3 + \(\frac{36}{5}\). ( 6 - \(\frac{\left(2,3+0,8\right).7}{0,1+6,9}\)) ] = \(\frac{15}{14}\)

\(\frac{39}{7}\): [ x : 1,3 + \(\frac{36}{5}\). ( 6 - \(\frac{3,1.7}{7}\)) ] = \(\frac{15}{14}\)

\(\frac{39}{7}\): [ x : 1,3 + \(\frac{36}{5}\). ( 6 - 3,1 ) ] = \(\frac{15}{14}\)

x : 1,3 + \(\frac{36}{5}\). 2,9 = \(\frac{39}{7}\): \(\frac{15}{14}\)

x : 1,3 + 20,88 = 5,2

x : 1,3 = - 15,68

x = - 15,68 . 1,3

x = - 20,384

ta có 

\(5\frac{4}{7}:\left\{x:1,3+8,4.\frac{6}{7}.\left[6-\frac{\left(2,3+5:6,25\right).7}{8.0,0125+6,9}\right]\right\}=1\frac{1}{14}\)

\(\Leftrightarrow\frac{39}{7}:\left\{x:1,3+7,2.\left[6-\frac{\left(2,3+0,8\right).7}{0,1+6,9}\right]\right\}=\frac{15}{14}\)

\(\Leftrightarrow\frac{39}{7}:\left\{x:1,3+7,2.\left[6-\frac{3,1.7}{7}\right]\right\}=\frac{15}{14}\)

\(\Leftrightarrow\frac{39}{7}:\left\{x:1,3+7,2.2,9\right\}=\frac{15}{14}\Leftrightarrow\left\{x:1,3+7,2.2,9\right\}=\frac{39}{7}:\frac{15}{14}\)

\(\Leftrightarrow x:1,3+20,88=5,2\Leftrightarrow x:1,3=-15,68\Leftrightarrow x=-20,384\)

wow, it's so hard, i am caculating it

X= -20,384

thank you very much

a: \(\Leftrightarrow\dfrac{39}{7}:\left\{x\cdot\dfrac{10}{13}+7.2\cdot\dfrac{257}{79}\right\}=\dfrac{15}{14}\)

\(\Leftrightarrow x\cdot\dfrac{10}{13}+\dfrac{9252}{395}=\dfrac{26}{5}\)

\(\Leftrightarrow x\simeq-23,69\)

b: TH1: x<1/2

Pt sẽ là 2-3x+1-2x=4

=>-5x+3=4

=>-5x=1

=>x=-1/5(nhận)

TH2: 1/2<=x<2/3

Pt sẽ là 2x-1+2-3x=4

=>1-x=4

=>x=-3(loại)

TH3: x>=2/3

Pt sẽ là 3x-2+2x-1=4

=>5x-3=4

=>5x=7

=>x=7/5(nhận)

a)\(\frac{-212}{351}\)

b)\(\frac{29}{10}\)

c)thiếu đề