Решите пожалуйста в) методом подстановк

Решите задачу:

$\left \{ {{-2x-y=12} \atop {3x+5y=4}} \right. \; \left \{ {{y=-2x-12} \atop {3x+5(-2x-12)=4}} \right. \; \left \{ {{y=-2x-12} \atop {3x-10x-60=4}} \right. \; \left \{ {{y=-2x-12} \atop {-7x=64}} \right. \\\\ \left \{ {{y=-2x-12} \atop {x=- \frac{64}{7}}} \right. \; \left \{ {{y=- \frac{128}{7}-12} \atop {x=- \frac{64}{7}}} \right. \; \left \{ {{y=- \frac{212}{7}} \atop {x=- \frac{64}{7}}} \right.\; \left \{ {{y=-30\frac{2}{7}} \atop {x=-9\frac{1}{7} }} \right. \\\\Otvet:\; \; (-9\frac{1}{7}\; ;\; -30\frac{2}{7})$