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? asked in Science & MathematicsMathematics · 10 years ago

Can you solve this equation?

ln(2x-5)- ln(x)=1/4

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3 Answers

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  • 10 years ago
    Favorite Answer

    ln[(2x - 5)/x] = 1/4

    => (2x - 5)/x = e^1/4

    so, 2x - 5 = xe^1/4

    => 2x - xe^1/4 = 5

    => x(2 - e^1/4) = 5

    i.e. x = 5/(2 - e^1/4) = 6.99 (3 s.f.)

    :)>

  • 10 years ago

    To answer this question, you must know the properties of ln. Remember:

    ln(B)+ln(A)=ln(AB)

    ln(B)-ln(A)=ln(B/A)

    2ln(B)=ln(B^2)

    e^ln(B)=B

    With these rules, we can proceed.

    so ln(2x-5)-ln(x)=1/4 becomes

    ln((2x-5)/x)=1/4

    Then, e^(ln(2x-5)/x)=e^(1/4)

    So, (2x-5)/x=e^(1/4)

    2x-5=xe^(1/4)

    2x=xe^(1/4)+5

    2x-xe^(1/4)=5

    (Remember e^(1/4) is just a number. All you have to do from here is combine the like terms of x, and divide by the resulting coefficient)

  • 10 years ago

    ln(2x-5) - ln(x) = 1/4

    or, ln((2x-5)/x) = 1/4

    or, (2x-5)/x = e^(1/4)

    or, 2x - 5 = xe^(1/4)

    or, x = 5/(2-e^(1/4)) = 5/(2-1.284) from calculator

    or, x = 6.983

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