#### Answer

$t=\left\{ -10,10 \right\}$

#### Work Step by Step

Factoring the given equation, $
x^2-100=0
,$ results to
\begin{array}{l}\require{cancel}
(x+10)(x-10)=0
.\end{array}
Equating each factor to zero (Zero Product Principle), then the solutions to the equation, $
(x+10)(x-10)=0
,$ are
\begin{array}{l}\require{cancel}
x+10=0
\\\\
x=-10
,\\\\\text{OR}\\\\
x-10=0
\\\\
x=10
.\end{array}
Hence, $
t=\left\{ -10,10 \right\}
.$