Question

18. If a + b + c = 6, then find the value of
12- a)3 + (2 – b)3 + (2 - 0)3 - 3 (2 - a) (2-6) (2-c)
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Answer 1

= 36-3a+6-3b+6+12(2-a)(2-c)

= 48-3a-3b+12(4-2c-2a+ac)

= 48-3a-3b+48-24c-24a+12ac

= 96-27a-24c+12ac-3b

= 96+3(-9a-8c+4ac)-3b

= 3(32-9a-8c+4ac-b)

Now solve it further using identies