Question

Решите 3. Решить Систему уровнений методом подстановки ​

Answer 1

$\left \{ {{2(x+2y)-3(x-y)=5} \atop {4(x+3y)-3y=17}} \right.\\\\\left \{ {{2x+4y-3x+3y=5} \atop {4x+12y-3y=17}} \right.\\\\\left \{ {{-x+7y=5} \atop {4x+9y=17}} \right.\\\\\ \left \{ {{x=7y-5} \atop {4(7y-5)+9y=17}} \right.\\\\\left \{ {{x=7y-5} \atop {28y-20+9y=17}} \right. \\\\\left \{ {{x=7y-5} \atop {37y=37}} \right.\\\\\left \{ {{y=1} \atop {x=7*1-5}} \right.\\\\\left \{ {{y=1} \atop {x=2}} \right.$

Ответ : (2 ; 1)