tolong dong soal mtk
Matematika
yaqool
Pertanyaan
tolong dong soal mtk
1 Jawaban
-
1. Jawaban whongaliem
[tex]2) 9^{x} - 12 . 3^{x} + 27 = 0[/tex]
[tex] (3^{2}) ^{x} - 12 . 3^{x} + 27 = 0[/tex]
[tex] (3^{x}) ^{2} - 12 . 3^{x} + 27 = 0[/tex]
[tex]( 3^{x} - 3) ( 3^{x} - 9) = 0[/tex]
[tex] 3^{x} - 3 = 0 .... atau ... 3^{x} - 9 = 0[/tex]
[tex] 3^{x} = 3 ... atau .. 3^{x} = 9[/tex]
[tex] 3^{x} = 3^{1} ... atau ... 3^{x} = 3^{2} [/tex]
x = 1 atau x = 2
x1 + x2 = 1 + 2
= 3 ....... jawaban : E
3) x² + x + c = 0 ⇒ a = 1 ; b = 1 ; c = c
α² + β² = 3
(α + b)² - 2.α.β = 3
(- b/a)² - 2 (c/a) = 3
(- 1/1)² - 2 (c/1) = 3
1 - 2c = 3
- 2c = 3 - 1
- 2c = 2
c = 2 / - 2
c = - 1 .... jawaban : B