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$$log x^{2}+3 log x - 10 = 0$$

 Sep 8, 2014

Best Answer 

 #1
avatar+33616 
+10

$$3\log{x}=\log{x^3}$$ using the property of logarithms that log(ab) = b*log(a)

$$\log{x^2}+\log{x^3}= \log{x^5}$$ using the property that log(a*b) = log(a) + log(b)

 

Using these, and adding 10 to both sides of the original equation, we have

$$\log{x^5}=10$$

 

This means that

$$x^5=10^{10}$$

 

Take the fifth root of both sides

$$x=10^2$$

 

or $$x=100$$

.
 Sep 8, 2014
 #1
avatar+33616 
+10
Best Answer

$$3\log{x}=\log{x^3}$$ using the property of logarithms that log(ab) = b*log(a)

$$\log{x^2}+\log{x^3}= \log{x^5}$$ using the property that log(a*b) = log(a) + log(b)

 

Using these, and adding 10 to both sides of the original equation, we have

$$\log{x^5}=10$$

 

This means that

$$x^5=10^{10}$$

 

Take the fifth root of both sides

$$x=10^2$$

 

or $$x=100$$

Alan Sep 8, 2014

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