Jika akar-akar persamaan x^2+ax+b memenuhi persamaan 2x^2-(a+3)x+(3b-2)=0, maka...
Matematika
Fahimafit99
Pertanyaan
Jika akar-akar persamaan x^2+ax+b memenuhi persamaan 2x^2-(a+3)x+(3b-2)=0, maka...
2 Jawaban
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1. Jawaban jlee55261
x^2 + ax + b = 0
x1 + x2 = -a
x1x2 = b
2x^2-(a+3)x+(3b-2)= 0
x1 + x2 = -a-3/2
x1x2 = 3b-2/2
-a = -a-3/2
-2a = -a-3
-2a+a = -3
-a = -3
a = 3
b = 3b-2/2
2b = 3b-2
2b-3b = -2
-b = -2
b = 2
Jadi persamaannya adalah :
x^2+3x+2 -
2. Jawaban Anonyme
jawab
(i) x² + ax + b = 0
(ii) 2x² -(a+3)x + (3b -2)= 0
2(i) = (ii)
2(x² + ax + b) = 2x² - (a+3)x + (3b -2)
2x² + 2ax + 2b= 2x² -(a+3)x + (3b -2)
2a = -(a+3)
2a = -a - 3
3a = - 3
a = -1
2b = 3b -2
-b = - 2
b = 2
maka
a= - 1, b = 2