Question

if a + b + c=0 then find the value of a^3+ b^3 + c^3

Answer 1

|a|=1, |b|=2, |c|=3

So a, b, c can be positive or negative. Thus, the value of the expression cannot be uniquely determined. 

NS

Statement 2:

a + b + c = 0

(a + b + c)^3 = a^3 + b^3 + c^3 + (3ab + 3bc + 3ca) (a + b + c) – 3abc

Substitute for a + b + c = 0 in the above equation:

0 = a^3 + b^3 + c^3 - 3abc 

=> 3abc = a^3 + b^3 + c^3

=> (a^3 + b^3 + c^3)/abc = 3 

Sufficient