SSC CGL 2022 PYQ — Question 57

SSC CGL - 13 April 2022 - Shift 2 • Quantitative Aptitude • Q57

if 22\sqrt{2}x3 - 33\sqrt{3}y3 = (2x−3y\sqrt{2}x-\sqrt{3}y)(Ax2 -Bxy + Cy2), then the value of (A2 + B2 + C2) is:

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 19

We have given, 22\sqrt{2}x3 - 33\sqrt{3}y3 = (2x−3y\sqrt{2}x-\sqrt{3}y)(Ax2 - Bxy + Cy2)........(1)

We know that a3 - b3 = (a - b) (a2 + ab + b2)

So,  22\sqrt{2}x3 - 33\sqrt{3}y3 =  (2x−3y\sqrt{2}x-\sqrt{3}y) (2x2 + 6\sqrt{6}xy + 3y2)..........(2).

Comparing eq 1 and eq 2

A = 2

B = -6\sqrt{6}

C = 3 

So, the value of (A2 + B2 + C2) = (22 + ( -6\sqrt{6})2 + 32) = 19