Hi Arav,
The question you have asked is Misc 4 of Ch4 Determinants, you can see the solution here http://teachoo.com/3309/695/Misc-4---Show-that-either-a---b---c-=-0-or-a-=-b-=-c/category/Miscellaneous/
To see solutions of Determinants, visit http://teachoo.com/subjects/cbse-maths/class-12th/ch4-12th-determinants/serial-order-wise/
To see all solutions of NCERT questions, visit http://teachoo.com/maths/