$\left\{\begin{array} { l } 4x-3y=24 \\ 5x-2y=9\end{array} \right.$
$\left\{\begin{array} { l } -8x+6y=-48 \\ 5x-2y=9\end{array} \right.$
$\left\{\begin{array} { l } -8x+6y=-48 \\ 15x-6y=27\end{array} \right.$
$7x=-21$
$x=-3$
$5 \times \left( -3 \right)-2y=9$
$y=-12$
$\left( x, y\right)=\left( -3, -12\right)$
$\left\{\begin{array} { l } 4 \times \left( -3 \right)-3 \times \left( -12 \right)=24 \\ 5 \times \left( -3 \right)-2 \times \left( -12 \right)=9\end{array} \right.$
$\left\{\begin{array} { l } 24=24 \\ 9=9\end{array} \right.$
$\left( x, y\right)=\left( -3, -12\right)$