Giải thích các bước giải:
\(\begin{array}{l}
DK:x > - 2\\
Q = \frac{1}{P}.\frac{{ - x}}{{\sqrt {x + 2} }} = \frac{1}{{\sqrt {x + 2} }}.\frac{{ - x}}{{\sqrt {x + 2} }}\\
= \frac{{ - x}}{{x + 2}} = \frac{{ - \left( {x + 2} \right) + 2}}{{x + 2}} = - 1 + \frac{2}{{x + 2}}\\
Do:Q \in Z\\
\to \frac{2}{{x + 2}} \in Z\\
\to x + 2 \in U\left( 2 \right)\\
\to \left[ \begin{array}{l}
x + 2 = 2\\
x + 2 = - 2\\
x + 2 = 1\\
x + 2 = - 1
\end{array} \right. \to \left[ \begin{array}{l}
x = 0\\
x = - 4\left( l \right)\\
x = - 1\\
x = - 3\left( l \right)
\end{array} \right.
\end{array}\)
