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? asked in Science & MathematicsMathematics · 8 years ago

How to sove an equation like 5^x=80?

That's the only thing my math teacher didn't get to for our finals review. I'm having trouble finding it in my math book. I'm pretty sure I know how to solve it but I want to make sure.

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  • 8 years ago
    Favorite Answer

    You have to make the bases equal to each other and then set the exponents into an equation and solve. Ex: 3^x=9....: 3^x=3^2....: x=2

  • 8 years ago

    Get the logarithm of both sides: ln 5^x=ln 80

    Then apply the property of logarithm: xln 5=ln 80

    Divide both sides by ln 5 to solve for x: x=ln 80/ln 5

  • 8 years ago

    This is a very very very very simple question

    5^x=80

    x=80/5

    Therefor x=16

    Source(s): My knowledge
  • Anonymous
    8 years ago

    To bring down the exponent "x", take logarithm on both sides. Logarithm has a property:

    log A^c = c log A

    log(5^x)=log 80

    xlog5=log80

    x= (log80)/log(5)

    x=2.72

    Source(s): Joseph's 487 questions to Algebra 2
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  • 8 years ago

    5^x = 80

    taking logarithm on both sides

    log(5^x) = log(80)

    x*log(5) = log(80)

    => x = log(80)/log(5)

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