If $a+b+c=11$ and $a b+b c+c a=28$, then find the value of $a^3+b^3+c^3-3 a b c$.
Answer & explanation
Correct answer: option 2
If $a+b+c=11$
$a b+b c+c a=28$
If the number of equations are less than the number of variables then we can put the extra variables according to our choice =
So here two equations given and three variables are present so put c = 0
$a+b=11$
$a b=28$
Find the value of $a^3+b^3$
$a^3+b^3$ = 113 - 3 × 11 × 28 = 407