Đáp án:
Giải thích các bước giải:
\(\begin{array}{l}
x + y = 3 \to x = 3 - y\\
Hpt \to \left\{ \begin{array}{l}
\left( {m - 1} \right)\left( {3 - y} \right) + y = 3m - 4\\
3 - y + \left( {m + 1} \right)y = m
\end{array} \right.\\
\to \left\{ \begin{array}{l}
3m - 3 - my + y + y = 3m - 4\\
3 - y + my + y = m
\end{array} \right.\\
\to \left\{ \begin{array}{l}
2y - my + 1 = 0\\
my - m + 3 = 0
\end{array} \right.\\
\to \left\{ \begin{array}{l}
2y - m + 4 = 0\\
my - m + 3 = 0
\end{array} \right.\\
\to \left\{ \begin{array}{l}
y = \frac{{m - 4}}{2}\\
{m^2} - 4m - 2m + 6 = 0
\end{array} \right.\\
\to \left[ \begin{array}{l}
m = 3 + \sqrt 3 \\
m = 3 - \sqrt 3
\end{array} \right. \to \left[ \begin{array}{l}
y = \frac{{ - 1 + \sqrt 3 }}{2}\\
y = \frac{{ - 1 - \sqrt 3 }}{2}
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = \frac{{7 - \sqrt 3 }}{2}\\
x = \frac{{7 + \sqrt 3 }}{2}
\end{array} \right.
\end{array}\)
