Explanation
Simplify the given expression step by step:
\[
2 \log \left(\frac{2}{5}\right) - \log \left(\frac{72}{125}\right) + \log 9
\]
1. Apply the logarithm power rule to the first term: \( a \log b = \log b^a \):
\[
\log \left(\frac{2}{5}\right)^2 = \log \left(\frac{4}{25}\right)
\]
So the expression becomes:
\[
\log \left(\frac{4}{25}\right) - \log \left(\frac{72}{125}\right) + \log 9
\]
2. Use the logarithm subtraction rule: \( \log a - \log b = \log \left(\frac{a}{b}\right) \):
\[
\log \left(\frac{4/25}{72/125}\right) + \log 9
\]
Simplifying the fraction:
\[
\frac{4/25}{72/125} = \frac{4 \times 125}{25 \times 72} = \frac{500}{1800} = \frac{5}{18}
\]
So we have:
\[
\log \left(\frac{5}{18}\right) + \log 9
\]
3. Use the logarithm addition rule: \( \log a + \log b = \log (a \times b) \):
\[
\log \left(\frac{5}{18} \times 9\right)
\]
Simplifying inside the logarithm:
\[
\frac{5 \times 9}{18} = \frac{45}{18} = \frac{5}{2}
\]
So the expression becomes:
\[
\log \left(\frac{5}{2}\right)
\]
4. Finally, express this as:
\[
\log \left(5 \times \frac{1}{2}\right) = \log 5 - \log 2
\]
Hence, the simplified expression is:
\[
1 - 2 \log 2
\]
Correct answer: D. 1 - 2log2