If, for a non zero x, 5x² + 7x + 5 =0, then the value of x³ + 1 over x³ is:

If, for a non zero x, 5x² + 7x + 5 =0, then the value of…

If, for a non zero x, 5x² + 7x + 5 =0, then the value of $x^3 + { {1} \over x^3}$ is:

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Correct answer: D

Explanation

The correct answer is option 4 i.e. ${{182} \over 125}$

5x² + 7x + 5 =0

⇒ x + 1/x = -7/5

$x^3 + { {1} \over x^3}$ = -343/125 + 21/5

= (525 - 343)/125 = 182/125