Question

$left { {{x+y=1} atop { x^{2 + y^{2} =25}} right.$

Answer 1

$left { {{x+y=1} atop {x^2+y^2=25}} right. =>left { {{x=1-y} atop {x^2+y^2=25}} right. =>(1-y)^2+y^2=25=>y^2-y-12=0\D=1+48=49\y_1=4\y_2=-3\x_1=-3\x_2=4$

Ответ:$(x_1;y_1)=(-3;4)\(x_2;y_2)=(4;-3)$