c) \(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)

\(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)=\frac{23}{27}-\frac{5}{9}\)

\(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)=\frac{23}{27}-\frac{15}{27}\)

\(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)=\frac{8}{27}\)

\(2+\frac{3}{4}x=\frac{7}{9}\div\frac{8}{27}\)

\(2+\frac{3}{4}x=\frac{7}{9}.\frac{27}{8}\)

\(2+\frac{3}{4}x=\frac{21}{8}\)

\(\frac{3}{4}x=\frac{21}{8}-2\)

\(\frac{3}{4}x=\frac{21}{8}-\frac{16}{8}\)

\(\frac{3}{4}x=\frac{5}{8}\)

\(x=\frac{5}{8}\div\frac{3}{4}\)

\(x=\frac{5}{8}.\frac{4}{3}\)

\(x=\frac{5}{6}\)

Vậy \(x=\frac{5}{6}\).

d) \(\left|x-\frac{1}{3}\right|-\frac{3}{4}=\frac{5}{3}\)

\(\left|x-\frac{1}{3}\right|=\frac{5}{3}+\frac{3}{4}\)

\(\left|x-\frac{1}{3}\right|=\frac{20}{12}+\frac{9}{12}\)

\(\left|x-\frac{1}{3}\right|=\frac{29}{12}\)

\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{3}=\frac{29}{12}\\x-\frac{1}{3}=-\frac{29}{12}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{11}{4}\\x=-\frac{25}{12}\end{cases}}\)

Vậy \(x\in\left\{\frac{11}{4};-\frac{25}{12}\right\}\).

-5.(x+1/5) -1/2.(x-2/3)=3/2x-5/6

-5x + (-1) -1/2x -1/3=3/2x-5/6

-5x-1/2x-3/2x=1+1/3-5/6

x.(-5-1/2-3/2)= 6/6+2/6+(-5/6)

x.(-10/2+(-1/2)+(-3/2))=3/6

x.6/2=1/2

x=1/2:6/2

x=1/6

Vậy x = 1/6

a, \(\frac{2}{3}x+\frac{5}{6}x+\frac{1}{2}=\frac{-3}{4}\)

\(\Leftrightarrow\frac{3}{2}x=\frac{-5}{4}\)

\(\Leftrightarrow x=\frac{-5}{6}\)

b, \(\frac{2}{5}+\frac{3}{5}.\left(3x-3,7\right)=\frac{-53}{10}\)

\(\Leftrightarrow\frac{3}{5}.\left(3x-\frac{37}{10}\right)=\frac{-57}{10}\)

\(\Leftrightarrow3x-\frac{37}{10}=\frac{-19}{2}\)

\(\Leftrightarrow3x=\frac{-29}{5}\)

\(\Leftrightarrow x=\frac{-29}{15}\)

a) \(\frac{2}{3}x+\frac{5}{6}x+\frac{1}{2}=-\frac{3}{4}\)

\(x\left(\frac{2}{3}+\frac{5}{6}\right)+\frac{1}{2}=-\frac{3}{4}\)

\(x\cdot\frac{3}{2}=\frac{-5}{4}\)

\(x=-\frac{5}{6}\)

\(\frac{2}{5}+\frac{3}{5}\left(3x-3,7\right)=-\frac{53}{10}\)

\(\frac{3}{5}\left(3x-\frac{37}{10}\right)=-\frac{57}{10}\)

\(3x-\frac{37}{10}=-\frac{19}{2}\)

\(3x=\frac{-29}{5}\)

\(x=\frac{-29}{15}\)

a, \(\frac{2}{3}x+\frac{5}{6}x+\frac{1}{2}=-\frac{3}{4}\)

\(\Leftrightarrow\frac{3}{2}x+\frac{5}{4}=0\Leftrightarrow\frac{3}{2}x=-\frac{5}{4}\Leftrightarrow x=\frac{-5}{6}\)

b, \(\frac{2}{5}+\frac{3}{5}\left(3x-3,7\right)=-\frac{53}{10}\)

\(\Leftrightarrow\frac{3}{5}\left(3x-\frac{37}{10}\right)=-\frac{57}{10}\Leftrightarrow3x-\frac{37}{10}=-\frac{10}{9}\Leftrightarrow x=-\frac{29}{15}\)

Ta có : 

\(\frac{x+1}{49}+\frac{x+2}{48}+\frac{x+3}{47}+\frac{x+4}{46}+\frac{x+5}{45}=-5\)

\(\Leftrightarrow\)\(\left(\frac{x+1}{49}+1\right)+\left(\frac{x+2}{48}+1\right)+\left(\frac{x+3}{47}+1\right)+\left(\frac{x+4}{46}+1\right)+\left(\frac{x+5}{45}+1\right)=-5+5\)

\(\Leftrightarrow\)\(\frac{x+50}{49}+\frac{x+50}{48}+\frac{x+50}{47}+\frac{x+50}{46}+\frac{x+50}{45}=0\)

\(\Leftrightarrow\)\(\left(x+50\right)\left(\frac{1}{49}+\frac{1}{48}+\frac{1}{47}+\frac{1}{46}+\frac{1}{45}\right)=0\)

Vì \(\frac{1}{49}+\frac{1}{48}+\frac{1}{47}+\frac{1}{46}+\frac{1}{45}\ne0\)

Nên \(x+50=0\)

\(\Rightarrow\)\(x=-50\)

Vậy \(x=-50\)

Chúc bạn học tốt ~ 

3.(x-1/2) -5(x+3/5)=-x+1/5

3x - 3/2 -5x +3 = -x+1/5 

3x-5x+x= 3/2-3+1/5

x.(3-5+1)=15/10 + (-30/10)+2/10

x.(-1)= -13/10

x = -13/10 : (-1)

x=13/10

vậy x=13/10

a, \(\frac{x-3}{y-2}=\frac{3}{2}\)và \(x-y=4\)

Theo bài ra ta có : 

\(\frac{x-3}{y-2}=\frac{3}{2}\Leftrightarrow2x-6=3y-6\Leftrightarrow2x=3y\Leftrightarrow\frac{x}{3}=\frac{y}{2}\)

Áps dụng tính chất dãy tỉ số bằng nhau ta đc :

\(\frac{x}{3}=\frac{y}{2}=\frac{x-y}{3-2}=\frac{4}{1}=4\)

\(\frac{x}{3}=4\Leftrightarrow x=12\)

\(\frac{y}{2}=4\Leftrightarrow y=8\)

Tương tự với b thôi bn.