Answer
$t=\left\{ 0,3 \right\}$
Work Step by Step
Factoring the given equation, $
3t-t^2=0
,$ results to
\begin{array}{l}\require{cancel}
t(3-t)=0
.\end{array}
Equating each factor to zero (Zero Product Principle), then the solutions to the equation, $
t(3-t)=0
,$ are
\begin{array}{l}\require{cancel}
t=0
,\\\\\text{OR}\\\\
3-t=0
\\\\
-t=-3
\\\\
t=3
.\end{array}
Hence, $
t=\left\{ 0,3 \right\}
.$