[tex]\displaystyle\bf\\\left \{ {{\dfrac{x}{3}-\dfrac{y}{9} =3 } \atop {\dfrac{x}{6} +\dfrac{y}{3}=-2 }} \right. \\\\\\\left \{ {{\dfrac{x}{3}\cdot 9-\dfrac{y}{9} \cdot 9=3\cdot 9 } \atop {\dfrac{x}{6}\cdot 6 +\dfrac{y}{3}\cdot 6=-2 \cdot 6}} \right. \\\\\\\left \{ {{3x-y=27} \ |\cdot 2\atop {x+2y=-12}} \right. \\\\\\+\left \{ {{6x-2y=54} \atop {x+2y=-12}} \right. \\----------\\7x=42\\\\x=6\\\\y=3x-27=3\cdot 6-27=18-27=-9\\\\Otvet: \ \Big(6 \ ; \ -9\Big)[/tex]