What is the standard form of y= (3x-1/2x^2)(4x-8) ?

$y = - 2 {x}^{3} + 16 {x}^{2} - 24 x$
$\text{expand factors using the FOIL method}$
$\Rightarrow 12 {x}^{2} - 24 x - 2 {x}^{3} + 4 {x}^{2}$
$= - 2 {x}^{3} + 16 {x}^{2} - 24 x \leftarrow \textcolor{red}{\text{ in standard form}}$