Matematika

Pertanyaan

tolong bantu yaa pake cara
nilai x yang memenuhi persamaan:
[tex] \frac{^{x}log 2 }{ ^{2}logx-4} = -\frac{1}{3} [/tex]
adalah....

1 Jawaban

  • jawab

    misalkan ˣlog 2 = a
    maka ²log x = 1/a

    [tex] \frac{ ^{x}log\, 2}{^2log\,x - 4} \, = \frac{-1}{3} [/tex]

    [tex]\frac{ a}{ \frac{1}{a} - 4} \, = \frac{-1}{3}[/tex]


    3a = -1/a + 4 ..}kalikan a
    3a² = -1 + 4a
    3a²  -  4a + 1= 0
    (3a -  1)(a - 1) = 0
    a=  1/3  atau a =  1

    ²log x = 1/a
    x = (2)^(1/a)
    a = 1/3 → x= (2)³ = 8
    a = 1 → x = (2)¹ = 2

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