8. x² - 7x + 12 = 0

a = 1, b = -7, c = 12 D = (-7)² - 4 * 1 * 12 = 49 - 48 = 1 x₁ = (7 + √1) / 2 * 1 = (7 + 1) / 2 = 8 / 2 = 4 x₂ = (7 - √1) / 2 * 1 = (7 - 1) / 2 = 6 / 2 = 3 Ответ: x₁ = 4, x₂ = 3