y=x^2-5
x^2+y^2=25
y - x^2 = -5
Складываем
y^2 + y - 20 = 0
D = 1 + 80 = 81
y12 = (-1 +- 9)/2 = -5 4
1. y = -5
-5 - x^2 = -5
x = 0
2. y = 4
4 - x^2 = -5
x^2 = 9
x = +- 3
ответ (0,-5) (3, 4) (-3, 4)
