Question

добрые люди помогите пожалуйста

Answer 1

1) x² - 5x + c = 0

x₁ = 3

x₁ + x₂ = 5   ⇒      x₂ = 5 - x₁ = 5 - 3 = 2

x₁ * x₂ = c

c = 3 * 2 = 6

c = 6

2) x² + bx + 18 = 0

x₁ = 3

x₁ * x₂ = 18    ⇒    x₂ = 18 : x₁ = 18 : 3 = 6

x₁ + x₂ = - b

- b = 3 + 6 = 9

b = - 9