Network
c. –3x² – 5x + 2 = 0
a = -3, b = -5, c = 2
D = (-5)² – 4(-3)(2)
D = 25 + 24 = 49
6. Jika nilai diskriminan persamaan kuadrat 3x² – 5x + c = 0 adalah 49, tentukan nilai c.
a = 3, b = -5
D = b² – 4ac
49 = (-5)² – 4(3)c
49 = 25 – 12c
12c = 25 - 49
12c = -24
c = -24/12 = -2
7. Ubahlah persamaan 3x² = 2x – 4 kedalam bentuk umum persamaan kuadrat.
3x² = 2x – 4
3x² - 2x + 4 = 0
8. Carilah himpunan penyelesaian dari persamaan kuadrat berikut.
a. x² – 5x + 6 = 0
p + q = -5
pq = 6
(x + p)(x + q)
(x - 3)(x - 2) = 0
x = 3 atau x = 2
b. x² + 2x – 15 = 0
p + q = 2
pq = -15
(x + 5)(x + q)
(x + 5)(x - 3) = 0
x = -5 atau x = 3
c. x² + 4x – 12 = 0
p + q = 4
pq = -12
(x + p)(x + q)
(x + 6)(x - 2) = 0
x = -6 atau x = 2
