SarkariPYQ

SSC CHSL 2023 PYQ — Question 54

SSC CHSL - 09 Aug 2023 - Shift 2 • Quantitative Aptitude • Q54

Back to paper

If x2+1x\frac{x^2+1}{x} =5, then find the value of x4 + 1x4\frac{1}{x^4} - 36

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. 491.

(x2 + 1)/x = 5

⇒ x + (1/x) = 5

⇒ x2 + (1/x2) = 52 - 2 = 25 - 2 = 23

⇒ x4 + (1/x4) = 232 - 2 = 529 - 2 = 527

⇒ x4 + (1/x4) - 36 = 527 - 36 = 491

Therefore, the value of the expression is 491.