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Represent $\frac{1}{3} \ln(x+2)^3 + \frac{1}{2}[\ln x - \ln (x^2+3x+2)^2]$ as a single logarithm

By Joseph Russell
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I am having some trouble trying to find the single logarithm for the following:

$$\frac{1}{3} \ln(x+2)^3 + \frac{1}{2}[\ln x - \ln (x^2+3x+2)^2]$$

I understand that I have to use the addition and subtraction rules but the coefficients are confusing me. These are some of the steps I took:

$$\begin{align} \frac{1}{3} \ln(x+2)^3 + \frac{1}{2} [\ln \frac{x}{(x^2+3x+2)^2}] \end{align}$$

Now from here, if I used the addition rule then what would happen to the coefficients? and also, is there a way for me to simplify the powers $2$ and $3$?

Hints would be appreciated!

Thanks!

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3 Answers

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$$\frac{1}{3} \ln(x+2)^3 + \frac{1}{2}[\ln x - \ln (x^2+3x+2)^2]$$

$$=\ln(x+2)+\frac{1}{2} \ln(x)-\ln(x^2+3x+2)$$

$$=\ln\frac{(x+2)(\sqrt x)}{x^2+3x+2}$$

$$=\ln \frac{\sqrt{x}}{x+1}$$

Properties of $\ln(x)$ that have been used :

$$a \ln(b)= \ln (b^a), ln(a)+ln(b)=\ln(ab)$$

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Hints: $a\ln b=\ln b^a$, $\ln a + \ln b = \ln ab$, $x^2+3x+2=(x+1)(x+2)$.

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Hint $$ b \cdot \log a = \log a^b$$

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