Answer
$\color{blue}{\dfrac{-3}{t+5}}
$
Work Step by Step
Factor the numerator and the denominator then cancel the common factors to obtain:
$\require{cancel}
=\dfrac{3(-1)(-3+t)}{(t+5)(t-3)}
\\=\dfrac{-3(t-3)}{(t+5)(t-3)}
\\=\dfrac{-3\cancel{(t-3)}}{(t+5)\cancel{(t-3)}}
\\=\color{blue}{\dfrac{-3}{t+5}}
$
