If a + b + c = 8 and ab + bc + ca = 14, then what is the value of (a3 + b3 + c3 - 3abc).
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Correct answer: A
Explanation
The correct answer is option 1 i.e. 176.
a3 + b3 + c3 - 3abc = (a + b + c)3 - 3(a + b + c)(ab + bc + ca)
⇒ a3 + b3 + c3 - 3abc = (8)3 - 3 × 8 × 14
⇒ a3 + b3 + c3 - 3abc = 512 - 336
⇒ a3 + b3 + c3 - 3abc = 176