Question

Решите систему линейных уравнений способом подстановки​

Answer 1

$\left \{ {{x = 6+4y} \atop {2x+7y=-78}} \right. \\\left \{ {{x=6+4y} \atop {2*(6+4y)+7y=-78}} \right. \\\left \{ {{x=6+4y} \atop {12+8y+7y=-78}} \right. \\\left \{ {{x=6+4y} \atop {15y = -90}} \right. \\\left \{ {{x=6+4y} \atop {y=-6}} \right. \\\left \{ {{x=6+4*(-6)} \atop {y=-6}} \right. \\\left \{ {{x=6-24} \atop {y=-6} \right.\\\left \{ {{x=-18} \atop {y=-6}} \right.$

Ответ: x = -18; y = -6