If x+1/x=7 , find the value of x^3+1/x^3 . - Quantitative Aptitude MCQ SSC CGL 2026 | ExamTest.live

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If x + \frac{1}{x} = 7, find the value of x^{3} + \frac{1}{x ^{3}} .

Solution & Step-by-step Explanation

We know the identity: x^{3} + \frac{1}{x ^{3}} = (x + \frac{1}{x})^{3} - 3 (x + \frac{1}{x}) Given x + \frac{1}{x} = 7 : x^{3} + \frac{1}{x ^{3}} = 7^{3} - 3 (7) x^{3} + \frac{1}{x ^{3}} = 343 - 21 = 322

Try it yourself before checking the explanation above.

If x + \frac{1}{x} = 7, find the value of x^{3} + \frac{1}{x ^{3}} .

343

332

340

322

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