x² + 8 = 9x x² + 9x = 3x 3(x² - 7) = 6
x² - 9x + 8 = 0 x² + 6x = 0 3x² - 21 = 6
(x - 8)(x - 1) = 0 x(x + 6) = 0 3x² - 27 = 0
x - 8 = 0 V x - 1 = 0 x = 0 V x + 6 = 0 3x² = 27
x = 8 V x = 1 x = 0 V x = -6 x² = 9
Product - som Factor buiten x = 3 V x = -3
methode haakjes Vorm x² = c