# Where did I go wrong in combining this expression?

The expression: $\ln(a+b) + \ln(a−b) − 9 \ln c$

My answer: $\ln[(a+b)(a-b)] / c^9$

...I'm guessing I should have multiplied $(a+b)(a-b)$ out? Or am I completely off? Help?

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## 1 Answer

You are close. The numerator is fine, but the denominator should be within the square brackets.

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Hah, that was actually a typo; I had it written correctly on paper. Lol thanks! –  Brandt Oct 8 '12 at 2:25