Để \(f\left(x\right)< 0,\forall x\in R\Leftrightarrow\left\{{}\begin{matrix}2m-3< 0\\\Delta'< 0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}m< \frac{3}{2}\\m^2-6m+9-\left(1-m\right)\left(2m-3\right)< 0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}m< \frac{3}{2}\\3m^2-11m+12< 0\left(ld\right)\end{matrix}\right.\Rightarrow m< \frac{3}{2}\)