log3(x - 5) + log3(x + 3) = 2 i need to solve for x. I know you can use the logx + logy = log(xy) but i can't get any further. help?
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$\displaystyle log_3(x-5) + log_3(x+3) = log_3((x-5)(x+3)) = 2 = log_3(3^2)$ I used the fact that $\displaystyle log_x(a) + log_x(b) = log_x(ab)$ and that $\displaystyle log_x(x) = 1$ and $\displaystyle log_k(x^n) = n \cdot log_k(x)$
Originally Posted by snypeshow log3(x - 5) + log3(x + 3) = 2 i need to solve for x. I know you can use the logx + logy = log(xy) but i can't get any further. help? First step: Determine the domain of this equation: $\displaystyle x-5>0~\wedge~x+3>0~\implies~\boxed{x>5}$ And now proceed as Defunkt has described.
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