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Homework Help: Solving this exponential equation

  1. Apr 19, 2009 #1
    1. The problem statement, all variables and given/known data
    Solve the equation e^x+10e^-x=7

    2. Relevant equations
    Logarithm rules and the natural logarithm

    3. The attempt at a solution
    Not really a calculus question but one i'm lost on nevertheless. I don't know how to go about solving this question at all. My first attempt was to factor out the e^x, but this got me nowhere. I know that this question has two answers (ln2 and ln5), but I cannot seem to figure out how to solve for these answers. Any help would be greatly appreciated, thanks in advance.
  2. jcsd
  3. Apr 19, 2009 #2


    Staff: Mentor

    Multiply both sides by e^x, which will give you an equation that is quadratic in form.
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