Giải thích các bước giải:
a,
ĐKXĐ:
\[\left\{ \begin{array}{l}
{x^2} - 4 \ne 0\\
x - 2 \ne 0\\
x + 2 \ne 0
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x \ne 2\\
x \ne - 2
\end{array} \right.\]
b,
\[\begin{array}{l}
A = \frac{{2x}}{{{x^2} - 4}} + \frac{3}{{x + 2}} - \frac{5}{{2 - x}}\\
\Leftrightarrow A = \frac{{2x}}{{\left( {x3 - 2} \right)\left( {x + 2} \right)}} + \frac{3}{{x + 2}} + \frac{5}{{x - 2}}\\
\Leftrightarrow A = \frac{{2x + 3\left( {x - 2} \right) + 5\left( {x + 2} \right)}}{{\left( {x - 2} \right)\left( {x + 2} \right)}}\\
\Leftrightarrow A = \frac{{10x - 4}}{{\left( {x - 2} \right)\left( {x + 2} \right)}} = \frac{{2\left( {5x - 2} \right)}}{{\left( {x - 2} \right)\left( {x + 2} \right)}}
\end{array}\]
