Question

Find a mathematical model for the verbal statement. (Use k for the constant of proportionality.)
The rate of change R of the temperature of an object is directly proportional to the difference between the temperature T of the object and the temperature Te of the environment.

Answer 1

dT/dt = k(T-Te)

Answer 2

wait - since this does not appear to be for a calculus class, Let's just say
R = k(T-Te)