Given the value of computer at t years
V(t) = 2000e^-.35t
The rate of the computer value falling is given by:
dv(t)/dt= 2000 x 0.35e^-0.25t= -700e^-0.35t
at t= 3years,
dv(t)/dt|t=3 =-700e^-0.35x3 = -245
The computer value falls at a rate of 245 after 3 years.