Question

Решите пожалуйста 99 а)

Answer 1

x² - 2xy + y² = 4
x² + xy = 4

(x - y)² = 4
x² + xy = 4

1) x - y = 2
x² + xy = 4

y = x - 2
x² + x(x - 2) = 4

y = x - 2
x² + x² - 2x - 4 = 0

y = x - 2
2x² - 2x - 4 = 0

y = x - 2
x² - x - 2 = 0

x₁ = 2, y₁ = 0
x₂ = -1, y₂ = -3

2) x - y = -2
x² + xy = 4

y = x + 2
x² + x(x + 2) = 4

y = x + 2
x² + x² + 2x - 4 = 0

y = x + 2
2x² + 2x - 4 = 0

y = x + 2
x² + x - 2 = 0

x₃ = -2, y₃ = 0
x₄ = 1, y₄ = 3

Ответ: (2; 0), (-2; 0), (-1; -3), (1, 3)