Solve log_x(64) = 3.
A2
B3
C4
D8
Explanation
- Turn the log into index form first: log_x(64) = 3 means x³ = 64.
- The cube root of 64 is 4, so x = 4.
- The unknown here is the base of the logarithm. The value of the logarithm is already given as 3.
- A logarithm base must be positive and cannot equal 1, which rules out several bases immediately.
- Prime factorising helps in harder versions of this question: 64 = 2⁶, and 2⁶ = (2²)³ = 4³.

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