Question 203783: ok. i have never understood logarithmic equations
do u mind helping?
4log(1-5x)= 2
i remeber having to do somthing like puting a 4 after log and it cancels and moves to the 2... something like that... can u show me the steps on how to solve logarithms :-]
Found 3 solutions by stanbon, nerdybill, RAY100:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 4log(1-5x)= 2
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A "log" is an exponent
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In your problem 4 times the "exponent" = 2
So the "exponent" must be 2/3 or 1/2.
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So log(1-5x) = 1/2
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You might ask: Exponent of what?
Since your problem does not show the base,
the word "log" means the base is 10.
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So 1-5x = 10^(1/2)
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Solve for "x"
5x = 1-sqrt(10)
x = -0.4325...
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Cheers,
Stan H.
Answer by nerdybill(7384)  (Show Source):
Answer by RAY100(1637) (Show Source):
You can put this solution on YOUR website! remember def of log,,,log(10)a=b if and only if 10^b =a
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and log a^b =b*log a
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4 log(1-5x) = 2
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log (1-5x)^4 =2
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10^2 =(1-5x)^4
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100 = (1-5x)^4
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taking 4th power of both sides,,
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(100)^(1/4) = 3.162 = (1-5x)
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3.162 -1 = 2.162 = -5x
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x= -.4325
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checking
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4 log(1-5x) =2
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4 log (1-5(-.4325) ) =2
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4log(3.162) =2
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4*.5 =2
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2=2,,,,,ok
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