a: \(\Leftrightarrow\dfrac{4}{33}:\left(x-1\right)=\dfrac{5}{3}:\dfrac{4}{9}=\dfrac{5}{3}\cdot\dfrac{9}{4}=\dfrac{45}{12}=\dfrac{15}{4}\)
=>\(x-1=\dfrac{4}{33}:\dfrac{15}{4}=\dfrac{16}{15\cdot33}\)
hay x=511/495
b: \(\Leftrightarrow x:\dfrac{1}{3}=\dfrac{17}{231}\)
=>x=17/231*1/3=17/693
c: \(\Leftrightarrow\dfrac{\dfrac{1}{6}+\dfrac{1}{3}}{\dfrac{1}{3}+\dfrac{7}{6}}\cdot x=\dfrac{2}{9}\)
\(\Leftrightarrow\dfrac{1}{2}:\dfrac{3}{2}\cdot x=\dfrac{2}{9}\)
=>1/3x=2/9
=>x=2/3