Soal mm bantu..........

Bab : Logaritma,Persamaan Eksponen, dan Persamaan Kuadrat

4^(y + 3x) = 64
4^(y + 3x) = 4^3
y + 3x = 3

xlog (x + 12) - 3. xlog 4 = -1
xlog (x + 12) - xlog 4^3 = -1
xlog ((x + 12)/64) = -1
x^-1 = (x + 12)/64
1/x = (x + 12)/64
64 = x(x + 12)
0 = x^2 + 12x - 64
(x + 16)(x- 4) = 0
x = -16 atau x = 4

Maka x = 4 [Jika x = -16, tidak ada di pilihan]
y + 3x = 3
y = 3 - 3(4)
y = 3 - 12
y = -9

x + 2y
= 4 + 2(-9)
= 4 - 18
= -14

Jawaban : D
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