[Jawaban:]

a. a. 3x⊃2; – 12 = 0
3x⊃2; – 12 = 0
Maka a = 3, b = 0, c = -12
>> Jadi Diskiriminan = 0⊃2; – 4(3)(–12) = 144

b. x⊃2; + 7x + 6 = 0
x⊃2; + 7x + 6 = 0
Maka a = 1, b = 7, c = 6
>> Jadi Diskiriminan = 7⊃2; – 4(1)(6) = 49 – 24 = 25

c. -3x⊃2; - 5x + 2 = 0
-3x⊃2; - 5x + 2 = 0
Maka a = -3, b = -5, c = 2
>> Jadi Diskiriminan = (–5)⊃2; – 4(–3)(2) = 25 + 24 = 49

6.) Jika nilai diskriminan persamaan kuadrat 3x2 – 5x + c = 0 adalah 49, tentukan nilai c.

[Jawaban:]

3x⊃2; – 5x + c = 0
Maka a = 3, b = -5

Jika D = b⊃2; - 4ac, D = 49
49 = (-5)⊃2; - 4.3.c
49 - 25 = -12.c
-12.c = 24
c = - 24/12
c = - 2

7. Ubahlah persamaan 3x2 =2x – 4 kedalam bentuk umum persamaan kuadrat.

[Jawaban:]

3x2 = 2x – 4
Maka 3x2 – 2x + 4 = 0

8. Carilah himpunan penyelesaian dari persamaan kuadrat berikut.

a. x2 – 5x + 6 = 0
b. x2 + 2x – 15 = 0
c. x2 + 4x – 12 = 0

[Jawaban:]

a. x2 – 5x + 6 = 0
x – 3 = 0 dan x – 2 = 0
Maka x = 3 atau x = 2