1.
a) \(\frac{11}{2}-\frac{2}{3}:\left|2x+-\frac{3}{2}\right|=3\)
               \(-\frac{2}{3}:\left|2x+-\frac{3}{2}\right|=3-\frac{11}{2}\)
               \(-\frac{2}{3}:\left|2x+-\frac{3}{2}\right|=-\frac{5}{2}\)
                          \(\left|2x+-\frac{3}{2}\right|=-\frac{2}{3}:\left(-\frac{5}{2}\right)\)
                          \(\left|2x+-\frac{3}{2}\right|=\frac{4}{15}\)
\(\Rightarrow\left|2x+-\frac{3}{2}\right|\in\text{{}\frac{4}{15};-\frac{4}{15}\)}
Nếu, \(2x+\left(-\frac{3}{2}\right)=\frac{4}{15}\)
                               \(2x=\frac{53}{30}\)
                                  \(x=\frac{53}{60}\)
Nếu, \(2x+\left(-\frac{3}{2}\right)=-\frac{4}{15}\)
                               \(2x=\frac{37}{30}\)
                                  \(x=\frac{37}{60}\)
Vậy \(x\in\text{{}\frac{53}{60};\frac{37}{60}\)}
b) \(\left|\frac{2}{7}x-\frac{1}{5}\right|-\left|-x+\frac{4}{9}\right|=0\)
    \(\left|\frac{2}{7}x-\frac{1}{5}\right|=\left|-x+\frac{4}{9}\right|\)
\(\Rightarrow\left|\frac{2}{7}x-\frac{1}{5}\right|\in\text{{}-x+\frac{4}{9};-\left(x+\frac{4}{9}\right)\)}
Nếu, \(\frac{2}{7}x-\frac{1}{5}=-x+\frac{4}{9}\)
                          \(x=\frac{203}{405}\)
Nếu, \(\frac{2}{7}x-\frac{1}{5}=-\left(-x+\frac{4}{9}\right)\)
         \(\frac{2}{7}x-\frac{1}{5}=x-\frac{4}{9}\)
            \(\frac{2}{7}x-x=\frac{1}{5}-\frac{4}{9}\)
                 \(-\frac{5}{7}x=-\frac{11}{45}\)
                           \(x=\frac{77}{225}\)
Vậy \(x\in\text{{}\frac{203}{405};\frac{77}{225}\)}

Có \(\frac{\frac{2}{7}+\frac{2}{5}+\frac{2}{17}-\frac{2}{239}}{\frac{3}{239}-\frac{3}{7}-\frac{3}{5}-\frac{3}{17}}\) : \(\frac{x}{3}\) = 2

    \(\frac{2.\left(\frac{1}{7}+\frac{1}{5}+\frac{1}{17}-\frac{1}{239}\right)}{-3.\left(\frac{-1}{239}+\frac{1}{7}+\frac{1}{5}+\frac{1}{17}\right)}\) : \(\frac{x}{3}\) = 2

\(\frac{-2}{3}\) : \(\frac{x}{3}\) = 2

\(\frac{-2}{3}\) . \(\frac{3}{x}\) = 2 

\(\frac{-2}{x}\) = 2 

\(\Rightarrow\) x = -1

Vậy x = -1

Chúc bạn học tốt !!! ^^ #Mango

Thank you 2 bn Nguyễn Thị Dương và bn nguyen thi thu hoai nha ^3^

\(\frac{x+6}{15}=\frac{5-x}{7}\)

\(\Leftrightarrow\left(x+6\right).7=\left(5-x\right).15\)

\(\Leftrightarrow7x+42=75-15x\)

\(\Leftrightarrow7x+15x=75-42\)

\(\Leftrightarrow22x=33\)

\(\Leftrightarrow x=\frac{3}{2}\)

=> 7.(x+6)= 15.(5-x)

=> 7x +7.6=15.5-15x

=> 7x + 42= 75 -15x

=> 7x+15x=75-42

=> 22x=33

=>x= 1,5

\(\frac{x+6}{15}=\frac{5-x}{7}\)

\(\Rightarrow\frac{x+6}{15}-\frac{5-x}{7}=0\)

\(\Rightarrow\frac{7.\left(x+6\right)}{7.15}+\frac{15.\left(x-5\right)}{7.15}=0\)

\(\Rightarrow\frac{7x+42}{105}+\frac{15x-75}{105}=0\)

\(\Rightarrow\frac{7x+42+15x-75}{105}=0\)

\(\Rightarrow\frac{22x-33}{105}=0\)

\(\Rightarrow22x+33=0\Rightarrow22x=33\)

\(\Rightarrow x=\frac{33}{22}=\frac{3}{2}\)

\(\frac{-6}{3}\left[x-\frac{1}{4}\right]=2x-1\)

\(-2x-\left[\frac{1}{4}.-2\right]=2x-1\)\

\(-2x-\frac{-1}{2}=2x-1\)

\(2x--2x=1-\frac{-1}{2}\)

\(\)\(4x=\frac{3}{2}\)

\(x=\frac{3}{2}:4\)

\(x=\frac{3}{8}\)