4)\(=>x=\dfrac{5}{12}:\left(\dfrac{2}{3}-\dfrac{1}{2}\right)=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)
5)\(=>\dfrac{9}{4}.\left(x-\dfrac{22}{3}\right)=\dfrac{3}{2}\)
\(=>x=\left(\dfrac{3}{2}:\dfrac{9}{4}\right)+\dfrac{22}{3}=\dfrac{2}{3}+\dfrac{22}{3}=\dfrac{24}{3}=8\)
\(=>\left(\dfrac{7}{10}-x\right):\dfrac{1}{2}=1-\dfrac{4}{5}=\dfrac{1}{5}\)
\(=>\dfrac{7}{10}-x=\dfrac{1}{5}\times\dfrac{1}{2}=\dfrac{1}{10}\)
\(=>x=\dfrac{7}{10}-\dfrac{1}{10}=\dfrac{6}{10}=\dfrac{3}{5}\)
\(6,\Rightarrow\left(\dfrac{7}{10}-x\right):\left(-\dfrac{1}{2}\right)+\dfrac{4}{5}=1\)
\(\Rightarrow\left(\dfrac{7}{10}-x\right):\left(-\dfrac{1}{2}\right)=\dfrac{1}{5}\)
\(\Rightarrow\dfrac{7}{10}-x=-\dfrac{1}{10}\)
\(\Rightarrow x=\dfrac{7}{10}-\dfrac{1}{10}\)
\(\Rightarrow x=\dfrac{3}{5}\)