Math Problem Statement

log_9 27 Evaluate this without a calculator

Solution

To evaluate log927\log_9 27 without a calculator, we can express both 9 and 27 as powers of the same base to simplify the logarithm.

Step 1: Rewrite 9 and 27 as powers of 3

  1. 9=329 = 3^2
  2. 27=3327 = 3^3

So, we can rewrite the logarithm as: log927=log3233\log_9 27 = \log_{3^2} 3^3

Step 2: Use the change of base formula

Using the property logambn=nmlogab\log_{a^m} b^n = \frac{n}{m} \log_a b, we can simplify as follows: log3233=32log33\log_{3^2} 3^3 = \frac{3}{2} \log_3 3

Step 3: Simplify log33\log_3 3

Since log33=1\log_3 3 = 1, we get: 321=32\frac{3}{2} \cdot 1 = \frac{3}{2}

Final Answer

log927=32\log_9 27 = \frac{3}{2}

Would you like more details or have any questions?


Here are some related questions to explore further:

  1. How do logarithmic properties help simplify complex expressions?
  2. What other methods can be used to evaluate logarithms without a calculator?
  3. How does changing the base of a logarithm affect its value?
  4. Can you express log279\log_{27} 9 and evaluate it?
  5. What happens if you evaluate log9(1/27)\log_9 (1/27) instead?

Tip: Remember, expressing numbers as powers of a common base is a powerful strategy for simplifying logarithmic expressions!

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Math Problem Analysis

Mathematical Concepts

Logarithms
Exponents
Change of Base

Formulas

log_b(x^m) = m * log_b(x)
log_{a^m} b^n = (n/m) * log_a(b)

Theorems

Logarithmic Change of Base

Suitable Grade Level

Grades 9-10