$$9qr( { S }^{ 2 } + { t }^{ 2 } )+18 { q }^{ 2 } { r }^{ 2 } ( { S }^{ 2 } + { t }^{ 2 } )$$
$9qr\left(t^{2}+S^{2}\right)\left(2qr+1\right)$
$9qrt^{2}+9qrS^{2}+18\left(Sqr\right)^{2}+18\left(qrt\right)^{2}$
