Решите систему с помощью подстановки ![latex] \left \{ {{x+2y=7} \atop {2y ^{2} +xy=14}} \right. [/latex]

[latex] \left \{ {{x+2y=7} \atop {2y^2+xy=14}} \right. \\ \\ \left \{ {{x=7-2y} \atop {2y^2+y(7-2y)=14}} \right. \\ \\ \left \{ {{x=7-2y} \atop {7y=14}} \right. \\ \\ \left \{ {{y=2} \atop {x=7-2*2}} \right. \\ \\ \left \{ {{y=2} \atop {x=3}} \right. [/latex] Ответ: (3;2)