Question

Решите системное уровнение {x-2y=5 y-x=-11

Answer 1

$left { {{x-2y=5} atop {y-x=-11}} right. = left { {{x-2y+(y-x)=5+(-11)} atop {y-x=-11}} right. = left { {{-y=-6 Rightarrow y=6} atop {(y rightarrow ) 6-x=-11 Rightarrow x=17}} right.$