How do you multiply (3t^2-2w)^2 ?

$9 {t}^{4} - 12 {t}^{2} w + 4 {w}^{2}$
${\left(a + b\right)}^{2} = {a}^{2} + 2 a b + {b}^{2}$ with $a = 3 {t}^{2}$ and $b = - 2 w$
${\left(3 {t}^{2} - 2 w\right)}^{2} = 9 {t}^{4} - 12 {t}^{2} w + 4 {w}^{2}$