Answer
$t=\left\{ -6,6 \right\}$
Work Step by Step
Factoring the given equation, $
x^2-36=0
,$ results to
\begin{array}{l}\require{cancel}
(x+6)(x-6)=0
.\end{array}
Equating each factor to zero (Zero Product Principle), then the solutions to the equation, $
(x+6)(x-6)=0
,$ are
\begin{array}{l}\require{cancel}
x+6=0
\\\\
x=-6
,\\\\\text{OR}\\\\
x-6=0
\\\\
x=6
.\end{array}
Hence, $
t=\left\{ -6,6 \right\}
.$