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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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 =]
Rewrite using log propertiesQuote:
Originally Posted by cbbplanet
$\displaystyle Log(x(x+3))=1$
rewrite in expo form.
$\displaystyle x(x+3)=10 \iff x^2+3x-10=0 $
$\displaystyle (x-2)(x+5)=0$
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.
