Question

(c) (a + b + c)2+(a - b + c)2 + (a + b - c)2​

Answer 1

Answer:

(a+b+c)²+(a-b+c)²+(a+b-c)²

=a²+b²+c²+2ab+2bc+2ca+a²+b²+c²-2ab-2bc+2ca+a²+b²+c²+2ab-2bc-2ca

=3a²+3b²+3c²+2ab-2bc+2ca

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