The correct answer is: [C}:  " 3 ⁻ ¹ " .
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Note:  " 3 = 3 ¹ " .
 → " 3 ⁻ ¹ = 1 / (3 ¹) = 1 /3 = 
 " .
 " .
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Let us consider the remaining answer choices:
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Choice [A}: " ( - 1)³ " . 
Note: " ( - 1)³ " = " { - 1 * - 1 * - 1 } " = " -1 " . 
 → " -1 " ≠ " 
 " .
 " .
 → So;  Choice [A} is INCORRECT.
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 Choice [B]: " (- 3)¹ " .
 Note: " ( - 3)¹ " = " -3 " . 
 → " -3 " ≠ " 
 " .
 " .
 → So; Choice [B] is INCORRECT.
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 → The correct answer is: [C]:  " 3 ⁻ ¹ . "
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Hope this was helpful!
Best of luck to you!
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