$\displaystyle

\frac {x^4+x^2y^2+y^4}{x^3-y^3} \div \frac{x^2-xy+y^2}{x-y}

$

$\displaystyle

\frac {x^4+x^2y^2+y^4}{(x-y)(x^2+xy+y^2)} \cdot \frac{x-y}{x^2-xy+y^2}

$

$\displaystyle

\frac {x^2+xy+y^2}{x^2+xy+y^2}

$

$\displaystyle

= 1

$

this correcT?