Persamaan kuadrat 3xkuadrat + px + 6p = 0 mempunyai akar x1 dan x2. Jika x1kuadrat+x2kuadrat=13, nilai p=

x1² + x2² = 13
(x1 + x2)² - 2.x1.x2 = 13
(-b/a)² - 2(c/a) = 13
(-p/3)² - 2(6p/3) = 13
(p²/9) - 12p/3 = 13
------------------------- × 9
p² - 36p = 117
p² - 36p - 117 = 0
(p - 39)(p + 3) = 0
p = 39 atau p = -3