#### Answer

$x=\left\{ 0,4 \right\}$

#### Work Step by Step

Factoring the given equation, $
12t=3t^2
,$ results to
\begin{array}{l}\require{cancel}
-3t^2+12t=0
\\\\
-3t(t-4)=0
.\end{array}
Equating each factor to zero (Zero Product Principle), then the solutions to the equation, $
-3t(t-4)=0
,$ are
\begin{array}{l}\require{cancel}
-3t=0
\\\\
t=\dfrac{0}{-3}
\\\\
t=0
,\\\\\text{OR}\\\\
t-4=0
\\\\
t=4
.\end{array}
Hence, $
x=\left\{ 0,4 \right\}
.$