Questions: Use the properties of logarithms
(a) 3 log3 2 - log3 72 =
Transcript text: Use the properties of logarithms
(a) $3 \log _{3} 2-\log _{3} 72=$
Solution
Solution Steps
To solve the given logarithmic expression using properties of logarithms, we can use the following steps:
Apply the property \( a \log_b c = \log_b (c^a) \) to the first term.
Use the property \( \log_b a - \log_b b = \log_b \left(\frac{a}{b}\right) \) to combine the terms.
Simplify the resulting expression.
Step 1: Apply the Power Rule
We start with the expression \( 3 \log_{3} 2 - \log_{3} 72 \). Using the property \( a \log_b c = \log_b (c^a) \), we can rewrite the first term:
\[
3 \log_{3} 2 = \log_{3} (2^3) = \log_{3} 8
\]
Step 2: Combine the Logarithms
Now, we can combine the two logarithmic terms using the property \( \log_b a - \log_b b = \log_b \left(\frac{a}{b}\right) \):
\[
\log_{3} 8 - \log_{3} 72 = \log_{3} \left(\frac{8}{72}\right)
\]
Step 3: Simplify the Fraction
Next, we simplify the fraction:
\[
\frac{8}{72} = \frac{1}{9}
\]
Thus, we have:
\[
\log_{3} \left(\frac{1}{9}\right)
\]
Step 4: Evaluate the Logarithm
Recognizing that \( \frac{1}{9} = 3^{-2} \), we can express the logarithm as:
\[
\log_{3} \left(3^{-2}\right) = -2
\]
Final Answer
The final result of the expression \( 3 \log_{3} 2 - \log_{3} 72 \) is:
\[
\boxed{-2}
\]