Question

{7х+7у=105
{2х=3у
Пж решите метоодом ПОДСТАНОВКИ ЭТУ СИСТЕМУ

Answer 1

⇒⇒⇒⇒⇒$left { {{7x+7y=105} atop {2x=3y}} right left { {{7x=105-7y} atop {2x=3y}} right. left { {{x=15-y} atop {2*(15-y)=3y}} right. left { {{x=15-y} atop {30=5y}} right. left { {{x=15-y} atop {y=6}} right. left { {{x=9} atop {y=6}} right.$