Question

Please answer it it's urgent.

Answer 1

yes it is Definitely correct as it is an identity

Answer 2

Hey Hanu ,

Here is your solution : 

Given,

⇒ ( a + b + c ) = 0

⇒ a + b = -c  ------ ( 1 )

By cubing both sides ,

⇒ ( a + b )³ = ( -c )³

⇒ a³ + b³ + 3 ab ( a + b ) = - c³

By putting back the value of ( a + b ) ,

⇒ a³ + b³ + 3 ab ( - c ) = - c³

⇒ a³ + b³ - 3abc = -c³

⇒ a³ + b³ + c³ - 3 abc = 0

⇒ a³ + b³ + c³ = 3 abc

Proved !!

Identities used to prove it :

= ( a + b )³

= ( a + b ) ( a + b ) ( a + b )

= ( a² + ab + ab + b² ) ( a + b )

= ( a² + 2 ab + b² ) ( a + b )

= ( a³ + a²b + 2 a²b + 2 ab² + ab² + b³ )

= ( a³ + 3 a²b + 3 ab² + b³ )

= a³ + b³ + 3 a²b + 3 ab²

= a³ + b³ + 3 ab ( a + b ).