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Bihar Police SI Algebraic Identities — practice questions

Explore 1 free Algebraic Identities questions in Bihar Police SI Quantitative Aptitude. Open each question or exercise to read its content, reference answers and available explanation.

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Algebraic Identities questions and exercises with answers

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If a is positive and a² + 1/a² = 7, then a³ + 1/a³ equals:Read the answer and worked solution →

Worked practice questions

If a is positive and a² + 1/a² = 7, then a³ + 1/a³ equals:

  1. 21
  2. 3√7
  3. 18
  4. 7√7
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Correct answer: C. 18

1. (a + 1/a)² = a² + 1/a² + 2 = 7 + 2 = 9, so a + 1/a = 3. 2. a³ + 1/a³ = (a + 1/a)³ − 3(a + 1/a). 3. = 27 − 9 = 18. _Source: RRB Group D CEN-02/2018 PYQ, Q.39._

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