Questions: Fill in the missing values to make the equations true.
(a) log2 11 + log2 5 = log2 □
(b) log3 □ - log3 4 = log3 7/4
(c) log9 32 = □ log9 2
Transcript text: Fill in the missing values to make the equations true.
(a) $\log _{2} 11+\log _{2} 5=\log _{2}$ $\square$
(b) $\log _{3}$ $\square$ $-\log _{3} 4=\log _{3} \frac{7}{4}$
(c) $\log _{9} 32=$ $\square$ $\log _{9} 2$
Solution
Solution Steps
Step 1: Solve part (a) using logarithm addition rule
The logarithm addition rule states that \( \log_b a + \log_b c = \log_b (a \cdot c) \).
Apply this rule to part (a):
\[
\log_2 11 + \log_2 5 = \log_2 (11 \cdot 5) = \log_2 55.
\]
Thus, the missing value is \( 55 \).
Step 2: Solve part (b) using logarithm subtraction rule
The logarithm subtraction rule states that \( \log_b a - \log_b c = \log_b \left( \frac{a}{c} \right) \).
Apply this rule to part (b):
\[
\log_3 x - \log_3 4 = \log_3 \left( \frac{x}{4} \right).
\]
Set this equal to \( \log_3 \frac{7}{4} \):
\[
\log_3 \left( \frac{x}{4} \right) = \log_3 \frac{7}{4}.
\]
Since the logarithms are equal, their arguments must be equal:
\[
\frac{x}{4} = \frac{7}{4}.
\]
Solve for \( x \):
\[
x = 7.
\]
Thus, the missing value is \( 7 \).
Step 3: Solve part (c) using logarithm power rule
The logarithm power rule states that \( \log_b a^k = k \log_b a \).
Rewrite \( \log_9 32 \) in terms of \( \log_9 2 \):
\[
\log_9 32 = \log_9 (2^5) = 5 \log_9 2.
\]
Thus, the missing value is \( 5 \).