\(\dfrac{-2}{3}=\dfrac{18}{x}\\ \Rightarrow x=18:\dfrac{-2}{3}\\ \Rightarrow x=-27\)
\(\dfrac{-2}{3}=\dfrac{18}{x}\)
\(\Leftrightarrow-2x=3\times18\)
\(\Leftrightarrow-2x=54\)
\(\Leftrightarrow x=54\div\left(-2\right)\)
\(\Leftrightarrow x=-27\)
Vậy \(x=-27\)