Respuesta:
[tex]S=\{(3,-3)\}[/tex]
Explicación paso a paso:
[tex]\left \{ {{4y+4x=0} \atop {y+2x=3}} \right. \\\\\left \{ {{2y+2x=0} \atop {y+2x=3}} \right. \\\\\left \{ {{2y+2x=0} \atop {-y-2x=-3}} \right. \\\\y=-3\\\\2(-3)+2x=0\\\\-6+2x=0\\\\2x=6\\\\x=\frac{6}{2}\\\\x=3[/tex]
