basic logarithm problem

Hi, I just don't get this sort of Logarithm problems that have same two variable in the equation.
The problem is:
Solve for x
log x + log(x+3)=1


thanks for the help =]

Quote:

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Originally Posted by cbbplanet

Hi, I just don't get this sort of Logarithm problems that have same two variable in the equation.
The problem is:
Solve for x
log x + log(x+3)=1


thanks for the help =]

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Rewrite using log properties



rewrite in expo form.





So x=2 or x=-5

But if you plug x=-5 into the original equation you end up with the log(-5)

which is undefined. So the only solution is x=2.