To find the values of the given logarithms without using a calculator, we can use the definition of logarithms and properties of exponents.
a. \( \log_2 8 \)
Since \( 8 = 2^3 \), we can write:
\[ \log_2 8 = \log_2 (2^3) = 3 \]
b. \( \log_5 25 \)
Since \( 25 = 5^2 \), we have:
\[ \log_5 25 = \log_5 (5^2) = 2 \]
c. \( \log_4 64 \)
Since \( 64 = 4^3 \) (because \( 4 = 2^2 \) and \( 64 = (2^2)^3 = 2^6 \)), we can write:
\[ \log_4 64 = \log_4 (4^3) = 3 \]
d. \( \log_3 9 \)
Since \( 9 = 3^2 \), we can write:
\[ \log_3 9 = \log_3 (3^2) = 2 \]
e. \( \log_5 625 \)
Since \( 625 = 5^4 \), we have:
\[ \log_5 625 = \log_5 (5^4) = 4 \]
So, the answers are:
a. \( 3 \)
b. \( 2 \)
c. \( 3 \)
d. \( 2 \)
e. \( 4 \)