Menentukan akar PK dgn memfaktorkan

Contoh Persamaan kuadrat dan Pemfaktorannya

1. X² + 8X + 12 = 0

( X + 6 )(X + 2) = 0

2. X² + 10X + 24 = 0

( X + 6 )(X + 4) = 0

3. X² + 7X + 10 = 0

( X + 5 )(X + 2) = 0

4. X² + 8X + 15 = 0

( X + 5 )(X + 3) = 0

5. X² + 9X + 20 = 0

( X + 6 )(X + 2) = 0

6. X² + 7X + 12 = 0

( X + 4 )(X + 3) = 0

7. X² + 8X + 16 = 0

( X + 4 )(X + 4) = 0

8. X² + 6X + 9 = 0

( X + 3 )(X + 3) = 0

9. X² + 6X + 8 = 0

( X + 4 )(X + 2) = 0

10. X² + 12X + 32 = 0

( X + 8 )(X + 4) = 0

11. X² + 11X + 10= 0

ð ( X + 1)(X + 10) = 0

12. X² + 10X + 21 = 0

( X + 7)(X + 3) = 0

13. X² + 11X + 30 = 0

( X + 5)(X + 6 ) = 0

14. X² + 5X + 6 = 0

( X + 2 )(X + 3 ) = 0

15. X² + 14X + 45 = 0

( X + 5 )(X + 9 ) = 0

16. X² + 15X + 56 = 0

( X + 8 )(X + 7 ) = 0

17. X² + 9X + 14 = 0

( X + 2 )(X + 7 ) = 0

18. X² + 9X + 18 = 0

( X + 6 )(X + 3 ) = 0

19. X² + 9X + 8 = 0

( X + 1 )(X + 8 ) = 0

20. X² + 6X - 27 = 0

( X - 3 )(X + 9 ) = 0

Pilih dua bilangan lalu bentuklah persamaan kuadratnya :

X² + bX + c = 0

Yang satu positif yang satu lagi negatif

Contoh 1 : -2 dan 8

Dikalikan hasilnya = -2 x 8 = -16 ===> c

Dijumlahkan hasilnya = -2 + 8 = 6 ===> b

Jadi PK adalah X² + 6X – 16 = 0

Contoh 2 : 2 dan -8

Dikalikan hasilnya = 2 x (-8) = -16

Dijumlahkan hasilnya = 2 + (-8) = -6

Jadi PK adalah X² - 6X – 16 = 0

Faktorkan Persamaan kuadrat berikut :

21. X² + 4X – 32 = 0

(X + 8)(X – 4) = 0

22. X² + 5X – 36 = 0

23. X² + 5X – 24 = 0

24. X² + 25X – 150 = 0

25. X² + 4X – 45 = 0

26. X² + 2X – 24 = 0

27. X² + 33X – 70 = 0

28. X² + 2X – 8 = 0

29. X² + 9X – 18 = 0

30. X² + 19X – 66 = 0

31. X² - 3X – 10 = 0

32. X² + 34X – 72 = 0