$$(8 { x }^{ 2 } - { z }^{ 2 } )(9z+ { x }^{ 2 } )$$
$\left(8x^{2}-z^{2}\right)\left(x^{2}+9z\right)$
$8x^{4}-9z^{3}+72zx^{2}-\left(xz\right)^{2}$
