How do you simplify -2(-3i)(7+6i)?

$- 36 + 42 i$
$\textcolor{\mathmr{and} a n \ge}{\text{Reminder }} \left({i}^{2} = {\left(\sqrt{- 1}\right)}^{2} = - 1\right)$
$= 6 i \left(7 + 6 i\right)$
$= 42 i + 36 {i}^{2} = - 36 + 42 i$