Question

помогите выделенной пожалуйста

Answer 1

$left { {{x-y=7} atop { x^{2} -2y=13}} right. \ \ left { {{y=x-7} atop { x^{2} -2cdot(x-7)=13}} right. \ \left { {{y=x-7} atop { x^{2} -2x+1=0}} right. \ \ left { {{y=1-7} atop {x=1}} right. \ \ left { {{y=-6} atop {x=1}} right.$