UPSC 2013 CDS 2 Math Paper

⇒x2−6=√6+x2−6=x
⇒x=3(x cannot be negative)
Trick:
Take two factors of 6 such that difference between them is 1.Here 3 and 2 are factors of 6 such that 3 – 2 = 1. Here all terms have ‘+’ sign. So the answer is 3.