Giải thích các bước giải:
\(\begin{array}{l}
a)\,DKXD:\,x \ne 0;\,x \ne \pm 2\\
b)\,A = \left( {\frac{{4x}}{{{x^2} - 4}} + \frac{{2x - 4}}{{x + 2}}} \right) \cdot \frac{{x + 2}}{{2x}} + \frac{2}{{2 - x}}\\
A = \frac{{4x}}{{{x^2} - 4}} \cdot \frac{{x + 2}}{{2x}} + \frac{{2\left( {x - 2} \right)}}{{x + 2}} \cdot \frac{{x + 2}}{{2x}} + \frac{2}{{2 - x}}\\
A = \frac{2}{{x - 2}} + \frac{{x - 2}}{x} - \frac{2}{{x - 2}}\\
A = \frac{{2x + \left( {x - 2} \right)\left( {x - 2} \right) - 2x}}{{x\left( {x - 2} \right)}}\\
A = \frac{{x - 2}}{x}
\end{array}\)
