Difficulty: Medium
Correct Answer: 0
Explanation:
Introduction / Context:Each logarithm can be rewritten using prime powers to obtain exact rational values. The goal is to compute each term exactly and then sum.
Given Data / Assumptions:
Concept / Approach:Use a = p^m, b = p^n ⇒ log_a b = n/m. Recognize 32 = 2^5, 8 = 2^3; 243 = 3^5, 3^7 is clear; 1296 = 36^2.
Step-by-Step Solution:
log₃₂(8) = log_{2^5}(2^3) = 3/5log₂₄₃(3^7) = log_{3^5}(3^7) = 7/5log₃₆(1296) = log_{36}(36^2) = 2Sum: 3/5 + 7/5 − 2 = 10/5 − 2 = 2 − 2 = 0Verification / Alternative check:Convert each to natural logs: ln 8/ln 32 + ln 3^7/ln 243 − ln 1296/ln 36; simplifying exponents yields the same rational values, confirming the result.
Why Other Options Are Wrong:3, 2, and 1 would require different exponents or bases; the exact arithmetic shows cancellation to zero.
Common Pitfalls:Misreading bases or exponents (e.g., treating 243 as 3^4) changes ratios and produces incorrect sums. Carefully factor numbers into prime powers.
Final Answer:0
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