Jawabanmu

2013-12-30T18:55:58+07:00
Jawaban C

x² + (4-1)x + 2 = 0
X² + 3x + 2 = 0
(x + 1) (x + 2)
α = -1 V β = -2
Jawaban paling cerdas!
2013-12-31T01:24:55+07:00
Pake rumus jumlah dan hasil kali akar
 \alpha . \beta = \frac{c}{a} \\
 2 \beta  . \beta = \frac{2}{1} \\
 2 \beta^2 = 2\\
 \beta =\pm 1

 \alpha + \beta = \frac{-b}{a}\\ 
 \alpha + \beta = \frac{-(a-1)}{1}\\
 \alpha + \beta = -a+1\\  
2 \beta  + \beta = -a+1\\
 3\beta = -a+1\\

untuk  \beta =1
3\beta = -a+1\\
3.1=-a+1\\
3=-a+1\\
a=-2

untuk  \beta =-1
3\beta = -a+1\\ 3.(-1)=-a+1\\ -3=-a+1\\ a=4

pilih yg positif (a>0) jadi
a=4
1 5 1