Question

Решите систему уравнений 1 ,х2+у2=74 и х-у=2

Answer 1

$\left \{ {{x^2+y^2=74} \atop {x-y=2}} \right. \\\ x=y+2 \\\ (y+2)^2+y^2=74 \\\ y^2+4y+4+y^2=74 \\\ 2y^2+4y-70=0 \\\ y^2+2y-35=0 \\\ D=1+35=36 \\\ y_1=-1-6=-7 \\\ y_2=-1+6=5 \\\ x_1=-7+2=-5 \\\ x_2=5+2=7$
ответ: (-5; -7); (7; 5)