SarkariPYQ

SSC Selection Post 2022 PYQ — Question 64

SSC Selection Post - Graduation Level - 9 Feb 2022 - Shift 3 • Quantitative Aptitude • Q64

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If 2x - 1x1\over{x}= 3, x ≠ 0, then simplify 8x6 - 25x3 - 1

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 20x3.

2x - 1/x = 3

⇒ (2x)3 - (1/x)3 - 3 × 2 × 3 = 33

⇒ 8x3 - 1/x3 = 45

⇒ 8x6 - 1 = 45x3

⇒ 8x6 - 25x3 - 1 = 45x3 - 25x3 = 20x3