SarkariPYQ

SSC CGL 2020 PYQ — Question 57

SSC CGL Tier II - Quant - 15 Nov 2020 • Quantitative Aptitude • Q57

Back to paper

If 3x2 - 5x + 1 = 0, then the value of (x2+1/9x2) is:

Show answer & explanation

Correct answer: C

Explanation

 The correct answer is option 3 i.e.  219\frac{1}{9} 

Concept

(a + b)2 = a2 + b2 + 2ab

Application

3x2 - 5x + 1 = 0

Diving the equation by 3x, we get

x + 1/ 3x = 5 /3

Squaring both sides

x2 + 1 / 9x2 + 2 x (x) x ( 1 / 3x) = 25 /9

x2 + 1 / 9x2 = 25 / 9 - 2 /3 =  219\frac{1}{9}