Question

a + b + c ka whole square

Answer 1

( a + b + c) ²

=[ ( a + b ) + c ]²

= (a+b)² + c² + 2(a+b)c

= a² + b² + 2ab + c² + 2ac + 2bc

= a² + b² + c² + 2ab + 2bc + 2ac

Answer 2

Hi friend, Harish here.

Here is your answer:

( a + b + c )² = ( a + b + c ) ( a + b + c)

⇒ (a×a)+(a×b)+(a×c)+(b×a)+(b×b)+(b×c)+(c×a)+(c×b)+(c×c)

⇒ a² + ab + ac + ab + b² + bc + ca + bc + c²

⇒ a² + b² + c² + (ab + ab) + (bc + bc) + (ac + ca)

⇒ a² + b² + c² + 2ab + 2bc + 2ca 

⇒ a² + b² + c² + 2(ab + bc + ca)
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Hope my answer is helpful to you.