3. Решите уравнение: a) 42-x2= 0 б) 16-9y2 = 0 в) (2-y)²-у(у+2,5)=4

a) 4² - x² = 0

16 - x² = 0

x² = 16

x = ±√16

x₁ = 4, x₂ = -4

б) 16 - 9y² = 0

9y² = 16

y² = 16/9

y = ±√(16/9)

y = ±(4/3)

y₁ = 4/3, y₂ = -4/3

в) (2 - y)² - y(y + 2,5) = 4

4 - 4y + y² - y² - 2,5y = 4

-6,5y = 0

y = 0

Ответ: a) x₁ = 4, x₂ = -4; б) y₁ = 4/3, y₂ = -4/3; в) y = 0