Đáp án:
x=-6
Giải thích các bước giải:
\(\begin{array}{l}
a.DK:\left\{ \begin{array}{l}
x + 1 \ne 0\\
2x - 6 \ne 0
\end{array} \right. \to \left\{ \begin{array}{l}
x \ne - 1\\
x \ne 3
\end{array} \right.\\
\to x \ne \left\{ { - 1;3} \right\}\\
b.P = \frac{{3x\left( {x + 1} \right)}}{{\left( {x + 1} \right)\left( {2x - 6} \right)}} = \frac{{3x}}{{2x - 6}}\\
P = 1 \to \frac{{3x}}{{2x - 6}} = 1\\
\to 3x = 2x - 6\\
\to x = - 6\left( {TM} \right)
\end{array}\)
