Question

Помогите решить систему уравнений. {х^2 + y^2 = 74 {x - y = 2

Answer 1

$\left \{ {{x^2+y^2=74} \atop {x-y=2}} \right. \\ \\ 1.x-y=2 \\ x=2+y \\ \\ 2.(2+y)^2+y^2=74 \\4+4y+y^2+y^2=74 \\ 2y^2+4y-70=0|:2 \\ y^2+2y-35=0 \\ D=4-4*1*(-35)=4+140=144 \\ y1=(-2+12)/2=5 \\ y2=(-2-12)/2=-7 \\ \\ 3. \left \{ {{y=5} \atop {x=7}} \right. \\ \left \{ {{y=-7} \atop {x=-5}} \right.$

Ответ: (7;5)(-5;-7)