bantu saya mengerjakan soal ini

Mapel : Matematika
Kelas : X SMA
Bab : Persamaan Kuadrat

Pembahasan :
2x² - ax = 6
2x² - ax - 6 = 0

Berdasarkan Teorema Vietta
X1 + X2 = -b/a
X1 + X2 = a/2
X1 = a/2 - X2

X1 . X2 = c/a
(a/2 - X2)(X2) = -3
-X2² + a/2X2 = -3
X2² - a/2 X2 = 3
X2(X2 - a/2) = 3
X2 = 3
X2 = 3 + a/2

Maka...
2X1 + X2 = 1
2(a/2 - X2) + X2 = 1
a - X2 = 1
X2 = a - 1
3 + a/2 = a - 1
6 + a = 2a - 2
2a - a = 6 + 2
a = 8

Jwaban : E