\(a,\frac{-2}{3}\div\left(\frac{1}{2}-3x\right)=\frac{5}{3}\)
\(\frac{1}{2}-3x=\frac{-2}{3}\div\frac{5}{3}\)
\(\frac{1}{2}-3x=\frac{-2}{5}\)
\(3x=\frac{1}{2}-\frac{-2}{5}\)
\(3x=\frac{9}{10}\)
\(x=\frac{9}{10}\div3=\frac{3}{10}\)
\(b,\frac{1}{7}\left|x\right|-\frac{4}{5}=\frac{1}{5}\)
\(\frac{1}{7}\left|x\right|=\frac{1}{5}+\frac{4}{5}=1\)
\(\left|x\right|=1\div\frac{1}{7}=7\)
\(\Leftrightarrow x=\pm7\)
-2/3:(1/2-3x)=5/3
(1/2-3x)=5/3.-3/2
(1/2-3x)=-5/2
3x=-5/2+1/2
3x=-3/2
x=-3/2:3/1
x=-3/2.1/3
x=-1/2