Question

{X-y =7; {(x+y)*2=54

Answer 1

$left { {{x-y=7} atop {(x+y)*2=54}} right. \x=y+7 \(y+7+y)*2=54 \2y+7=27 \2y=20 \y=10 \x=10+7=17$
Ответ: (17;10)