x² + px + q = 0
1) x₁ = 5 x² = 4
- p = x₁ + x₂
- p = 5 + 4
- p = 9
p = - 9
q = x₁ * x₂
q = 5 * 4
q = 20
x² - 9x + 20 = 0
2) x₁ = 12 x² = -8
- p = 12 - 8
- p = 4
p = - 4
q = 12 * (-8)
q = - 96
x² - 4x - 96 = 0
x² + px + q = 0
1) x₁ = 5 x² = 4
- p = x₁ + x₂
- p = 5 + 4
- p = 9
p = - 9
q = x₁ * x₂
q = 5 * 4
q = 20
x² - 9x + 20 = 0
2) x₁ = 12 x² = -8
- p = x₁ + x₂
- p = 12 - 8
- p = 4
p = - 4
q = x₁ * x₂
q = 12 * (-8)
q = - 96
x² - 4x - 96 = 0