Question

Find $x^3-y^3$, if $x-y=5$ and $xy=16$.

Answer 1

We know that $x^3-y^3=(x-y{)}^3+3xy(x-y)$

Substituting the given values:
$\therefore x^3-y^3=(5{)}^3+3(16\left)\right(5)$

$=125+240$

$=365$