9514 1404 393
Answer:
x = 1/7
Explanation:
x³ = 1/343
x = 1/∛343 = 1/7
The positive value of x is 1/7.
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Additional comment
A square root (or any even-index root) will have both positive and negative real values. A cube root (or any odd-index root) will have only one real value, whose sign will match the sign of the value being rooted.
343^(-1/3) is the cube root of a positive number, so it will be a positive real number.