$${ \left( \frac{ 3x }{ 11 } - \frac{ 11y }{ 13 } + \frac{ 13z }{ 15 } \right) }^{ 2 }$$
$\frac{\left(585x-1815y+1859z\right)^{2}}{4601025}$
$\frac{26xz}{55}-\frac{6xy}{13}-\frac{22yz}{15}+\frac{9x^{2}}{121}+\frac{121y^{2}}{169}+\frac{169z^{2}}{225}$
