Theo đề, ta có:
\(\left\{{}\begin{matrix}\dfrac{3}{2a}=3\\-\dfrac{9-4ac}{4a}=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=1\\9-4ac=-4a\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}9-4c=-4\\a=1\end{matrix}\right.\)
=>a=1 và c=13/4