Đáp án:
$\begin{array}{l}
\frac{{1 - 3x}}{{2x}} + \frac{{3x - 2}}{{2x - 1}} + \frac{{3x - 2}}{{2x - 4{x^2}}}\\
= \frac{{\left( {1 - 3x} \right).\left( {2x - 1} \right) + \left( {3x - 2} \right).2x - \left( {3x - 2} \right)}}{{2x\left( {2x - 1} \right)}}\\
= \frac{{ - 6{x^2} + 5x - 1 + 6{x^2} - 4x - 3x + 2}}{{2x\left( {2x - 1} \right)}}\\
= \frac{{ - 2x + 1}}{{2x\left( {2x - 1} \right)}}\\
= - \frac{1}{{2x}}\\
Khi:x = \frac{1}{{808}}\\
\Rightarrow A = \frac{{ - 1}}{{2.\frac{1}{{808}}}} = \frac{{ - 1}}{{\frac{1}{{404}}}} = - 404
\end{array}$
