\(1\dfrac{5}{6}=\dfrac{-x}{5}\)
\(\Leftrightarrow\dfrac{11}{6}=\dfrac{-x}{5}\)
\(\Leftrightarrow\left(-x\right).6=11.5\)
\(\Rightarrow\left(-x\right).6=55\)
\(\Rightarrow\left(-x\right)=55:6\)
\(\Rightarrow\left(-x\right)=\dfrac{55}{6}\)
\(\Rightarrow x=\dfrac{-55}{6}\)
Vậy...
\(\Rightarrow\) -x : 5 = 1 \(\dfrac{5}{6}\)
\(\Rightarrow\) -x : 5 = \(\dfrac{11}{6}\)
\(\Rightarrow\) -x = \(\dfrac{11}{6}\) : 5
\(\Rightarrow\) -x = \(^{\dfrac{11}{30}}\)
\(\Rightarrow\) -x = \(\dfrac{-11}{30}\)