tolong jawab secepatnya, thx

Mapel : Matematika
Kelas : X SMA
Bab : Eksponen dan Logaritma

Pembahasan :
20.

x'log (2x - 3) - x'Log (x + 6) + x'log (x + 2) = 1
x'log [(2x - 3) : (x + 6) . (x + 2)] = 1
x'log [(2x - 3)/(x + 6) . (x + 2)] = 1
x'log [(2x - 3)(x + 2)/(x + 6)] = x'log x
(2x - 3)(x + 2)/(x + 6) = x
(2x - 3)(x + 2) = x² + 6x
2x² + x - 6 = x² + 6x
x² - 5x + 6 = 0
(x - 3)(x - 2) = 0
x = 2
x = 3

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21.

9^[³log (2x - 1)] = 25
3^(³log (2x - 1)²] = 25
(2x - 1)² = 25
2x - 1 = ± 5

2x - 1 = 5
2x = 6
x = 3

2x - 1 = -5
2x = -4
x = -2

Hp : {-2 , 3}

Jawaban : D