Answer
$T(t)=T_{s}+D_{0}e^{-kt}$
Work Step by Step
Newton's Law of Coollng is described on p. 377:
If an object has an initial temperature that is $D_{0}$ degrees warmer
than the surrounding temperature $T_{s}$,
then at time $t$ the temperature $T(t)$ of the object is modeled by the function
$T(t)=T_{s}+D_{0}e^{-kt}$
where the constant $k>0$ depends on the size and type of the object.