\(-\dfrac{5}{6}-x=\dfrac{7}{12}+\left(-\dfrac{1}{3}\right)\)
\(\Leftrightarrow-\dfrac{5}{6}-x=\dfrac{7}{12}-\dfrac{1}{3}\)
\(\Leftrightarrow-\dfrac{5}{6}-x=\dfrac{7}{12}-\dfrac{4}{12}\)
\(\Leftrightarrow-\dfrac{5}{6}-x=\dfrac{3}{12}\)
\(\Leftrightarrow-x=\dfrac{3}{12}+\dfrac{5}{6}\)
\(\Leftrightarrow-x=\dfrac{3}{12}+\dfrac{10}{12}\)
\(\Leftrightarrow-x=\dfrac{13}{12}\)
\(\Leftrightarrow x=-\dfrac{13}{12}\)