\(a,\dfrac{x}{3}=-\dfrac{1}{2}\)
\(\Leftrightarrow2x=-1.3\)
\(\Leftrightarrow2x=-3\)
\(\Leftrightarrow x=-\dfrac{3}{2}\)
\(b,\dfrac{x}{3}=\dfrac{3}{x}\)
\(\Leftrightarrow x.x=3.3\)
\(\Leftrightarrow x^2=9\)
\(\Leftrightarrow x=\pm3\)
a)\(\dfrac{x}{3}=-\dfrac{1}{2}\)
\(\Rightarrow2x=-3\)
\(\Rightarrow x=-\dfrac{3}{2}\)
b)\(\dfrac{x}{3}=\dfrac{3}{x}\)
\(\Rightarrow x^2=9\)
\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)
\(a,\dfrac{x}{3}=\dfrac{-1}{2}\\ \Rightarrow x=\dfrac{3\times\left(-1\right)}{2}=\dfrac{-3}{2}\\ b,\dfrac{x}{3}=\dfrac{3}{x}\\ \Rightarrow x^2=9\\ \Rightarrow\left[{}\begin{matrix}x^2=3^2\\x^2=\left(-3\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)