`X = 8r^3, Y = 3s^3`

$\displaystyle{64}{{r}}^{{9}}+{27}{{s}}^{{6}}={\left({8}{{r}}^{{3}}+{3}{{s}}^{{3}}\right)}{\left({16}{{r}}^{{6}}-{24}{{r}}^{{3}}{{s}}^{{3}}+{6}{{s}}^{{6}}\right)}\usepackage{cmbright}\Huge\$