The voltage V across a resistor in an electric circuit is the product of the resistance and the current. If the current I (in A) varies with time t (in s) according to the relation I = 6.00 + 0.05t and the resistance varies with time according to the relation R = 12.00 -0.10t, find the rate of change of the voltage when t= 4.00 s dv at (Type an integer or decimal rounded to the nearest thousandth as needed.)