Matematika

Pertanyaan

³log x +³log (2x-3)<3
Tolong bangett yaa
³log x +³log (2x-3)<3 Tolong bangett yaa

2 Jawaban

  • ³log x +³log (2x-3) < 3
    ³log(x(2x-3)) < ³log27
    ⇔ x(2x - 3) < 27
    ⇔ 2x² - 3x - 27 < 0
    ⇔ (2x - 9)(x + 3) < 0
    -3 < x < 9/2

    syarat logaritma
    x > 0
    dan
    2x - 3 > 0
    2x > 3
    x > 3/2

    jadi 
    HP : {x| 3/2 < x < 9/2}

  • [tex]^3log x +^3log (2x-3)<3 \\ ^3log x (2x-3)<3 \\ ^3log(2 {x}^{2} - 3x) < ^3log {3}^{3} \\ 2 {x}^{2} - 3x < {3}^{3} \\ 2 {x}^{2} - 3x - 27 < 0 \\ (2 {x} - 9)(x + 3) < 0 \\ \{- 3 < x < \frac{9}{2}\}[/tex]
    Ingat syarat logaritma:
    [tex]x > 0[/tex]
    dan
    [tex]2x - 3 > 0 \\ x > \frac{3}{2} [/tex]
    jadi himpunan penyelesaian:
    [tex]\{ \frac{3}{2} < x < \frac{9}{2} \}[/tex]