Question

The answer is opt-d but how is this the answer
plz don't spam

Answer 1

Answer:

As option B AND C are correct identities

Answer 2

Step-by-step explanation:

(a+b+c)²= a²+b²+c²+2(ab+bc+ca)

0²= a²+b²+c²+2(ab+bc+ca)

-2(ab+bc+ca)= a²+b²+c²

therefore,

-2= a²+b²+c²/ab+bc+ca

HOPE IT HELPS :)