Answer
$2(10+t)(10-t)$
Work Step by Step
Factoring the $GCF=
2
$, the given expression, $
200-2t^2
,$ is equivalent to
\begin{array}{l}
2(100-t^2)
\end{array}
Using $x^2-y^2=(x+y)(x-y)$ or the factoring of the difference of 2 squares, then the factored form of the expression, $
2(100-t^2)
,$ is
\begin{array}{l}
2(10+t)(10-t)
\end{array}