SSC CHSL 2023 PYQ — Question 70

SSC CHSL 2023 - 02 Aug 2023 - Shift 3 • Quantitative Aptitude • Q70

If x=1x−5x = \frac{1}{x-5} (x > 0),then the value of x+1xx + \frac1 x is :

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 29\sqrt29.

Given that

If x=1x−5x = \frac{1}{x-5} (x > 0), 

⇒ x - 5 = 1/x

⇒ x - 1/x = 5

Square both side 

⇒ x2 + 1/x2 -2 = 25

⇒ x2 + 1/x2  = 25 + 2 = 27

⇒ (x + 1/x)2 - 2 = 27

⇒ (x + 1/x)2 = 29

⇒ x + 1/x =  29\sqrt29