Page 86 - TUTORIAL MATEMATIKA IPA KELAS XI-2

SUKU BANYAK
1
2
Hasil bagi = 2 − 5 + 2 = (2 − 1)( − 2) sehingga diperoleh akar-akar lainnya adalah
2
dan 2.
HP = {-1, ½ , 2}

2
3
46. Persamaan 2 + 3 + + 8 = 0 mempunyai sepasang akar berkebalikan. Tentukan p.
1
Misal: =
1
2
1 8
. . = − = −4 → = −4
3
2
3
2 2
3 3 5
+ + = − = − → + − 4 = − → + =
1
1
2
2
1
3
2
2 2 2
1 5
. + + . = → . − 4 − 4 = 1 − 4( + ) = 1 − 4. =
2
2
2
1. 3
2
3
1
1
2
1
2 2 2 2

→ 1 − 10 = → −9 = → = −18
2 2

2
3
47. (−2) + 4(−2) + 7. (−2) + = 0 → −8 + 16 − 14 + = 0 → = 6
3
2
→ + 4 + 7 + 6 = 0
2
7
4
2
2
2
2
+ + = ( + + ) − 2( + + ) = ( ) − 2 = 2.
2
1
3
2 3
1 3
1 2
3
2
1
1
1

2
3
2
2
2
3
48. 4 √ +2 −3 −6 = 2 √4 +4 −8 → 2 2√ +2 −3 −6 = 2 √4 +4 −8
2
2
3
2
2
3
2√ + 2 − 3 − 6 = √4 + 4 − 8 → 4( + 2 − 3 − 6) = 4 + 4 − 8
2
3
2
3
→ 4 + 4 − 16 + 16 = 0 → + − 4 + 4 = 0
4
. . = − = − = −4
3
1
2
1

−12
49. + + = − → + + 2 + + 4 = − 1 = 12
1
1
3
2
1
1

→ 3 + 6 = 12 → = 2 , = 2 + 2 = 4 , = 2 + 4 = 6
1
1
2
3
−( +8)
. . = − → 2.4.6 = − → 48 = + 8 → = 40
1
2
3
1
p – 36 = 40 – 36 = 4

2
3
50. + 2 − 15 + = 0
Misal : =
2
1
2
+ + = − → + + = − → 2 + = −2 → = −2 − 2 … ( )
3
3
1
3
3
1
1
2
1
1

1
2 2
. . = − → . . = − → . = − → (−2 − 2 ) = − … ( )
1
3
1
3
3
1
1
2
1 1 1

2
2
. + + . = → + 2 = −15 → + 2 (−2 − 2 ) = −15
1
1. 3
2
1
1
1
1
1 3
3
2

2
2
→ − 4 − 4 = −15
1
1
1
2
→ 3 + 4 − 15 = 0
1
1
5
→ (3 − 5)( + 3) = 0 → = , = −3
1
1
1
1
3
2
5 5 5 400 400
→ = → − = ( ) . (−2 − 2. ) = − , =
1
3 3 3 27 27
2
→ = −3 → − = (−3) . (−2 − 2. (−3)) = 36 , = −36
1
LEARNING IS FUN 85