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Homework Help: Solving Exponential Equation

  1. Apr 12, 2009 #1
    1. The problem statement, all variables and given/known data

    3^x + x = 4

    solve for x.
    2. Relevant equations

    I'm thinking of using the logarithm laws. log(a.b) = log a + logb log(a/b) = log a - log b

    log(a^b) = bloga

    3. The attempt at a solution
    Well if I isolate the exponential
    3^x = 4-x

    take logs on both sides

    xlog3 = log(4-x)

    I can't seem to get the x out of the log.
  2. jcsd
  3. Apr 12, 2009 #2


    User Avatar
    Homework Helper

    You won't be able to find a solution algebraically. However the value for x is quite obvious. Take a good look at the equation in its original form.
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