Đáp án:
\(x = 0\,\,hoac\,\,\,x = 3.\)
Giải thích các bước giải:
\(\begin{array}{l}
A = \frac{{2x + 8}}{{2x + 1}} = \frac{{2x + 1 + 7}}{{2x + 1}} = 1 + \frac{7}{{2x + 1}}\\
\Rightarrow \left( {2x + 8} \right)\,\, \vdots \,\,\left( {2x + 1} \right)\\
\Rightarrow 7\,\, \vdots \,\,\left( {2x + 1} \right)\\
Ma\,\,\,7\,\,chia\,\,het\,\,cho\,\,\,1\,\,va\,\,\,7\\
\Rightarrow \left[ \begin{array}{l}
2x + 1 = 1\\
2x + 1 = 7
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
2x = 0\\
2x = 6
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
x = 0\\
x = 3
\end{array} \right..\\
Vay\,\,\,x = 0\,\,hoac\,\,\,x = 3.
\end{array}\)
