Câu 2
\[\begin{array}{l}
\left( \Delta \right):Ax + By + C = 0,\overrightarrow n \left( {A;B} \right) \\
{d_1} \to \overrightarrow {{n_1}} \left( {3; - 4} \right) \\
{d_2} \to \overrightarrow {{n_2}} \left( {5;12} \right) \\
I\left( {1;1} \right) \in \left( \Delta \right) \to A + B + C = 0\left( 1 \right) \\
A = \left( \Delta \right) \cap \left( {{d_1}} \right),\,\,\,B = \left( \Delta \right) \cap \left( {{d_2}} \right) \\
{\Delta _{MAB}} \to c{\rm{os}}\left( {\overrightarrow {{n_1}} ;\overrightarrow {{n_2}} } \right) = c{\rm{os}}\left( {\overrightarrow n ;\overrightarrow {{n_2}} } \right) \\
\leftrightarrow \frac{{33}}{{65}} = \frac{{\left| {5A + 12B} \right|}}{{13\sqrt {{A^2} + B} }} \\
B = 1\,\,\left( {{d_1}} \right) \to 464{A^2} - 3000A - 2511 = 0 \\
\left[ \begin{array}{l}
A = \frac{{ - 3}}{4} \\
A = \frac{{837}}{{116}} \\
\end{array} \right. \\
\to A = \frac{{ - 3}}{4} \to C = \frac{1}{4} \to \left( {{\Delta _1}} \right):3x - 4y - 1 = 0 \\
A = \frac{{837}}{{116}} \to C = \frac{{ - 953}}{{116}} \to \left( {{\Delta _2}} \right):837x + 116y - 953 = 0 \\
\end{array}\]
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