Exponent equivalence: Evaluate (4×4×4×4×4×4)^5 × (4×4×4)^8 ÷ (4)^3 and express the result as (64)^?. Determine the integer exponent ?.

Difficulty: Easy

Correct Answer: 17

Explanation:


Introduction / Context:
This exercise tests exponent rules and base conversion. The idea is to combine products and quotients of powers of 4, then rewrite the final result as a power of 64. Recognizing that 64 = 4^3 is the shortcut to matching bases.



Given Data / Assumptions:

  • (4×4×4×4×4×4) = 4^6.
  • (4×4×4) = 4^3.
  • Expression: (4^6)^5 × (4^3)^8 ÷ 4^3.
  • Target form: (64)^? with 64 = 4^3.


Concept / Approach:
Apply exponent rules: (a^m)^n = a^(mn) and a^p × a^q = a^(p+q). For division, a^p ÷ a^q = a^(p−q). After simplifying to a single power of 4, convert to a power of 64 using base equivalence.



Step-by-Step Solution:

(4^6)^5 = 4^(6*5) = 4^30.(4^3)^8 = 4^(3*8) = 4^24.Product: 4^30 × 4^24 = 4^(30+24) = 4^54.Divide by 4^3 → 4^(54 − 3) = 4^51.Since 64 = 4^3, write 4^51 = (4^3)^(17) = 64^17.


Verification / Alternative check:
Reverse substitution: 64^17 = (4^3)^17 = 4^(51), exactly matching the simplified exponent on 4. Hence ? = 17.



Why Other Options Are Wrong:
10, 11, 15, and 16 do not satisfy 3×? = 51. Only 17 makes 64^? equal to 4^51.



Common Pitfalls:
Adding instead of multiplying exponents in (a^m)^n, or forgetting to subtract exponents when dividing like bases.



Final Answer:
17

More Questions from Simplification

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion