решите систему уравнений х^2+y^2=50 и xy=7

2ху = 14

плюсуем

х2 + 2ху + у2 = 64

(x + y)2 = 64

x+y = 8

xy=7

(1; 7), (7; 1)

X^2+y^2=50 и xy=7

X^2+y^2=50 и y=7/x

X^2+(7/x)^2=50 и y=7/x

X1=-7; x2=7; x3=-1; x4= 1

Y1=-1; y2=1; y3=-7; y4=7