Evaluate piecewise functions

$g(t) = \begin{cases} -2t(t+1) & , & t<6 \\\\ \dfrac{5t}{6} & , & 6\leq t\leq 12\\\\ 2t^2+3t & , & t >12\end{cases}$ $g(12)=$ [[☃ numeric-input 1]]