Đáp án:
\(A = \left\{ {\frac{3}{2}} \right\}\)
Giải thích các bước giải:
\(\begin{array}{l}
A = \left\{ {x \in R|\,\,\,\frac{{2{x^2} - 5x + 3}}{{{x^2} - 4x + 3}} = 0} \right\}\\
DK:\,\,\,{x^2} - 4x + 3 \ne 0 \Leftrightarrow \left\{ \begin{array}{l}
x \ne 1\\
x \ne 3
\end{array} \right..\\
\,\frac{{2{x^2} - 5x + 3}}{{{x^2} - 4x + 3}} = 0\\
\Leftrightarrow 2{x^2} - 5x + 3 = 0\\
\Leftrightarrow \left[ \begin{array}{l}
x = 1\,\,\,\,\left( {ktm} \right)\\
x = \frac{3}{2}\,\,\,\left( {tm} \right)
\end{array} \right.\\
\Rightarrow A = \left\{ {\frac{3}{2}} \right\}.
\end{array}\)
