Question

Помогите с системой пожалуйста! :(

Answer 1

$\left \{ {{-x-9y=33} \atop {-x+9y=-21}} \right. \; \left \{ {{-2x=12} \atop {9y=x-21}} \right. \; \left \{ {{9y=-27} \atop {x=-6}} \right. \; \left \{ {{y=-3} \atop {x=-6}} \right.$

(-6,-3)