Question

y=x^2-5
x^2+y^2=25
решите систему

Answer 1

y=x^2-5

x^2+y^2=25

====

y - x^2 = -5

x^2+y^2=25

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)