Find the solution of the logarithmic equation &; Find the solution of the logarithmic equation ?????? no clue!
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Originally Posted by evinez Find the solution of the logarithmic equation $\displaystyle log_2(x^2 - 5x - 20) = 2$ $\displaystyle x^2 - 5x - 20 = 2^2 = 4$ etc. -Dan
Originally Posted by evinez $\displaystyle log(x) + log(x - 20) = log(7x)$ $\displaystyle log(x(x - 20)) = log(7x)$ $\displaystyle x(x - 20) = 7x$ etc. -Dan
Hello, For the second one, remember that $\displaystyle \log(a)+\log(b)=\log(a+b)$ Then if $\displaystyle \log(x)=\log(y)$, $\displaystyle x=y$ remember that x has to be positive and superior to 20 as x and x-20 have to be positive
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