If a + b + c = 12 and ab + bc + ca = 22, then what is the value of $a^3 +b^3 + c^3 -3abc $ ?
Answer & explanation
Correct answer: option 2
If x + y = n
then, $x^3 + y^3$ = n3 - 3 × n × xy
If a + b + c = 12
ab + bc + ca = 22
what is the value of $a^3 +b^3 + c^3 -3abc $
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
If a + b = 12
ab = 22
what is the value of $a^3 +b^3 $ = 123 - 3 × 12 × 22
what is the value of $a^3 +b^3 $ = 1728 - 792 = 936